Scientific American Supplement, No. 344, August 5, 1882
by
Various
Part 2 out of 3
COMPOUND BEAM ENGINE.
The engine represented in Figs. 1 to 4 herewith is intended for a mill,
and is of 530 to 800 indicated horse-power, the pressure being seven
atmospheres, and the number of revolutions forty-five per minute. As
will be seen by the drawing each cylinder is placed in a separate
foundation plate, the two connecting rods acting upon cranks keyed
at right angles upon the shaft, W, which carries the drum, T. The
high-pressure cylinder, C, is 760 mm diameter, the low pressure cylinder
being 1,220 mm. diameter, and the piston speed 2.28 m. The drum, which
also fulfills the purpose of a fly wheel, is provided with twenty-eight
grooves for ropes of 50 mm. diameter. With the exception of the
cylinders, pistons, valves, and valve chests, the engines are of the
same size, corresponding to the equal maximum pressures which come into
action in each cylinder, and in this respect alone the engine differs in
principle from an ordinary twin machine.
[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 1]
The steam passes from the stop-valve, A, Fig. 4, through the steam pipe,
D, to the high pressure cylinder, C, and having done its work, goes into
the receiver, R, where it is heated. From the receiver it is led into
the low-pressure cylinder, C1, and thence into the condenser. Provision
is made for working both engines independently with direct steam when
desired, suitable gear being provided for supplying steam of the proper
pressure to the condensing engine, so that each engine shall perform
exactly the same amount of work. The starting gear consists of a
hand-wheel, H, which controls the stop valve, A, and of another h, which
opens the valves for the jackets of the cylinders and receiver. The
hand-wheel, h1 and h2, govern the valves, which turn the steam direct
into the two cylinders. There are also lever, g, which opens the
principal injection cock, H1, and the auxiliary injection cock, H2, the
function of which is to assist in forming a speedy vacuum, when the
engine has been standing for some time.
[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 2]
The drum is 6.08 m. diameter, the breadth being 2.04 m., with a total
weight of 33,000 kilos. The beams are of cast iron with balance weights
cast on. The connecting rods and cross beams are of wrought iron, and
the cranks, crank shaft, piston rods, valve rods, etc., of steel. The
bed-plate for the main shaft bearings are cast in one piece with the
standards for the beam, which are connected firmly together by the
center bearing, M M1, which is cast in one piece, and also by the
diagonal bracing piece, N N1. The construction of the cylinder and valve
chests is shown in Fig. 1. The working cylinder is in the form of a
liner to the cylinder, thus forming the steam jacket, with a view to
future renewal. This lining has a flange at the lower part for bolting
it down, being made steam-tight by the intervention of a copper packing
ring. There is a similar ring at the upper part which is pressed down by
the cylinder cover. The latter is cast hollow and strengthened by ribs.
The pistons are provided with cast iron double self-expanding packing
rings. For preventing accidents by condensed water, spring safety
valves, ss and s1 s1, are connected to the valve chests. The valve gear,
which is arranged in the same manner for both cylinders, is actuated
by shafts, w and w1, rotated by toothed wheels as shown. Motion is
communicated from the way-shafts, w and w1, by the eccentrics, and the
eccentric rods, e1 e2 e3 e4, and the levers and rods belonging thereto,
to the short steam valve rocking shafts levers, f1 f2 f3 f4, and the
exhaust valve rocking shafts, k1 k2 k3 k4, the bearings of which are
carried on brackets above the valve chests, which, being furnished with
tappet levers, raise and lower the valves.
[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 3]
The valves are conical, double-seated, and of cast iron, and the inlet
and outlet valves are placed the one above the other, the seats being
also conically ground and inserted through the cover of the valve chest.
Both inlet and outlet valves are actuated from above, and are removable
upward, an arrangement which admits of the valves being more easily
examined than when the two are actuated from different sides of the
valve chest. To carry out this idea the inlet valves are furnished with
two guides, which, passing upward through the stuffing-box, are attached
to a hard steel cross piece, which receives the action of a bent catch
turning on a pin attached to the levers, t1, t2, t3, t4. The exhaust
valves, on the contrary, have only one guide each, which passes upward
through the seat of the admission valve, through the valve itself by
means of a collar, and through the stuffing-box. It is furnished with
hard steel armatures, through which the levers, z1 z2, Fig. 3, act upon
the exhaust valves.
[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 4]
The governor effects the acceleration or retardation of the loosening of
the catch actuating the steam valve by means of hard steel projections
on the shaft, v1, the position of which, by means of levers, is
regulated by the governor, which in its highest position does not allow
the lifting of the inlet valve at all. The regulation of the expansion
by the governor from 0 to 0.45 takes place generally only in the case of
the high-pressure cylinder, while the low-pressure cylinder has a fixed
rate of expansion. Only when the low-pressure cylinder is required
to work with steam direct from the boiler is the governor applied to
regulate the expansion in it. An exact action in the valve guides and
a regular descent is secured by furnishing them with small dash pot
pistons working in cylinders. Into them the air is readily admitted by
a small India-rubber valve, but the passage out again is controlled at
pleasure.--_The Engineer_.
* * * * *
TO DETECT ALKALIES IN NITRATE OF SILVER--Stolba recommends the salt
to be dissolved in the smallest quantity of water, and to add to
the filtered solution hydrofluosilicic acid, drop by drop. Should a
turbidity appear an alkaline salt is present. But should the liquid
remain limpid, an equal volume of alcohol is to be added, which will
cause a precipitate in case the slightest trace of an alkali be present.
* * * * *
POWER HAMMERS WITH MOVABLE FULCRUM.
[Footnote: Paper read before the Institution of Mechanical
Engineers.--_Engineering_.]
By DANIEL LONGWORTH, of London.
The movable-fulcrum power hammer was designed by the writer about five
and a half years ago, to meet a want in the market for a power hammer
which, while under the complete control of only one workman, could
produce blows of varying forces without alteration in the rapidity with
which they were given. It was also necessary that the vibration and
shock of the hammer head should not be transmitted to the driving
mechanism, and that the latter should be free from noise and liability
to derangement. The various uses to which the movable fulcrum hammers
have been put, and their success in working[1]--as well as the
importance of the general subject which includes them, namely, the
substitution of stored power for human effort--form the author's excuse
for now occupying the time of the meeting.
[Footnote 1: The hammers have been for some years used by A. Bamlett, of
Thirsk; the American Tool Company, of Antwerp; Messrs. W.&T. Avery, of
Birmingham; Pullar & Sons, of Perth; Salter & Co., of West Bromwich;
Vernon Hope & Co., of Wednesbury, etc.; and also for stamps by Messrs.
Collins & Co., of Birmingham, etc.]
Until these hammers were introduced, no satisfactory method had been
devised for altering the force of the blow. The plan generally adopted
was to have either a tightening pulley acting on the driving belt, a
friction driving clutch, or a simple brake on the driving pulley, put in
action by the hand or foot of the workman. Heavy blows were produced
by simply increasing the number of blows per minute (and therefore the
velocity), and light blows by diminishing it--a plan which was quite
contrary to the true requirements of the case. To prevent the shock
of the hammer head being communicated to the driving gear, an elastic
connection was usually formed between them, consisting of a steel spring
or a cushion of compressed air. With the steel spring, the variation
which could be given in the thickness of the work under the hammer was
very limited, owing to the risk of breaking the spring; but with the
compressed air or pneumatic connection the work might vary considerably
in thickness, say from 0 to 8 in. with a hammer weighing 400lb. The
pneumatic hammers had a crank, with a connecting rod or a slotted
crossbar on the piston-rod, a piston and a cylinder which formed the
hammer-head. The piston-rod was packed with a cup leather, or with
ordinary packing, the latter required to be adjusted with the greatest
nicety, otherwise the piston struck the hammer before lifting it, or
else the force of the blow was considerably diminished. As the piston
moved with the same velocity during its upward and downward strokes,
and, in the latter, had to overtake and outrun the hammer falling under
the action of gravity, the air was not compressed sufficiently to give
a sharp blow at ordinary working speeds, and a much heavier hammer was
required than if the velocity of the piston had been accelerated to a
greater degree.
As it is impossible in the limits of this paper to describe all the
forms in which the movable fulcrum hammers have been arranged, two types
only will be selected taken from actual work; namely, a small planishing
hammer, and a medium-sized forging hammer.[1]
[Footnote 1: To the makers, Messrs. J. Scott Rawlings & Co, of
Birmingham, the author is indebted for the working drawings of these
hammers.]
The small planishing hammer, Figs. 1 to 3, next page, is used for
copper, tin, electro, and iron plate, for scythes, and other thin work,
for which it is sufficient to adjust the force of the blow once for all
by hand, according to the thickness and quality of the material before
commencing to hammer it. The hammer weighs 15 lb., and has a stroke
variable from 21/2 in. to 91/2 in., and makes 250 blows per minute. The
driving shaft, A, is fitted with fast and loose belt pulleys, the belt
fork being connected to the pedal, P, which when pressed down by the
foot of the workman, slides the driving belt on to the fast pulley and
starts the hammer; when the foot is taken off the pedal, the weight on
the latter moves the belt quickly on to the loose pulley, and the hammer
is stopped. The flywheel on the shaft, A, is weighted on one side,
so that it causes the hammer to stop at the top of its stroke after
working; thus enabling the material to be placed on the anvil before
starting the hammer. The movable fulcrum, B, consists of a stud, free to
slide in a slot, C, in the framing, and held in position by a nut and
toothed washer. On the fulcrum is mounted the socket, D, through which
passes freely a round bar or rocking lever, E, attached at one end to
the main piston, F, of the hammer, G, and having at the other extremity
a long slide, H, mounted upon it. This slide is carried on the
crank-pin, I, fastened to the disk, J, attached to the driving shaft, A.
The crank-pin, in revolving, reciprocates the rocking lever, E, and
main piston, F, and through the medium of the pneumatic connection, the
hammer, G. The slide, H, in revolving with the crank-pin, also moves
backward and forward along the rocking lever, approaching the fulcrum,
B, during the down-stroke of the hammer, and receding from it during
the up-stroke. By this means the velocity of the hammer is considerably
accelerated in its downward stroke, causing a sharp blow to be given
while it is gently raised during its upward stroke.
To alter the force of the blow, the hammer, G, is made to rise and fall
through a greater or less distance, as may be required, from the fixed
anvil block, K, after the manner of the smith giving heavy or light
blows on his anvil. It is evident that this special alteration of the
stroke could not be obtained by altering the throw of a simple crank and
connecting rod; but by placing the slot, C, parallel with the direction
of the rocking lever, E, when the latter is in its lowest position, with
the hammer resting on the anvil, and with the crank at the top of its
stroke, this lowest position of the rocking lever and hammer is made
constant, no matter what position the fulcrum, B, may have in the slot,
C. To obtain a short stroke, and consequently a light blow, the fulcrum
is moved in the slot toward the hammer, G; and to produce a long stroke
and heavy blow the fulcrum is moved in the opposite direction.
Fig. 3 gives the details of the pneumatic connection between the main
piston and the hammer, in which packing and packing glands are dispensed
with. The hammer, G, is of cast steel, bored out to fit the main piston,
F, the latter being also bored out to receive an internal piston, L. A
pin, M, passing freely through slots in the main piston, F, connects
rigidly the internal piston, L, with the hammer, G. When the main piston
is raised by the rocking lever, the air in the space, X, between the
main and internal pistons, is compressed, and forms an elastic medium
for lifting the hammer; when the main piston is moved down, the air in
the space, Y, is compressed in its turn, and the hammer forced down to
give the blow. Two holes drilled in the side of the hammer renew the air
automatically in the spaces, X and Y, at each blow of the hammer.
Figs. 4 to 6, on the next page, represent the medium size forging
hammer, for making forgings in dies, swaging and tilting bars, and
plating edged tools, etc.
The hammer weighs 1 cwt., has a stroke variable from 4 in. to 141/2 in.,
and gives 200 blows per minute; the compressed air space between the
main piston and the hammer is sufficiently long to admit forgings up to
3 in. thick under the hammer.
To make forgings economically, it is necessary to bring them into the
desired form by a few heavy blows, while the material is still in a
highly plastic condition, and then to finish them by a succession of
lighter blows. The heavy blows should be given at a slower rate than the
lighter ones, to allow time for turning the work in the dies or on the
anvil, and so to avoid the risk of spoiling it. In forging with the
steam hammer the workman requires an assistant, who, with the lever
of the valve motion in hand, obeys his directions as to starting and
stopping, heavy or light blows, slow or quick blows, etc; the quickest
speed attainable depending on the speed of the arm of the assistant.
In the movable-fulcrum forging hammer the operations of starting and
stopping, and the giving of heavy or light blows, are under the complete
control of one foot of the workman, who requires therefore no assistant;
and by properly proportioning the diameter of the driving pulley and
size of belt to the hammer, the heavy blows are given at a slower rate
than the light ones, owing to the greater resistance which they offer to
the driving belt.
In this hammer the pneumatic connection, the arrangements for the
starting, stopping, and holding up of the hammer, as well as those for
communicating the motion of the crank-pin to the hammer by means of
a rocking lever and movable fulcrum, are similar to those in the
planishing hammer, differing only in the details, which provide double
guides and bearings for the principal working parts.
[Illustration: LONGWORTH'S POWER HAMMER WITH MOVABLE FULCRUM.]
The movable fulcrum, B, Figs. 4 and 5, consists of two adjustable steel
pins, attached to the fulcrum lever, Q, and turned conical where they
fit in the socket, D. The fulcrum lever is pivoted on a pin, R, fixed in
the framing of the machine, and is connected at its lower extremity
to the nut, S, in gear with the regulating screw, T. The to-and-fro
movement of the fulcrum lever, Q, by which heavy or light blows are
given by the hammer, is placed under the control of the foot of the
workman, in the following manner: U is a double-ended forked lever,
pivoted in the center, and having one end embracing the starting pedal,
P, and the other end the small belt which connects the fast pulley
on the driving shaft, A, with the loose pulley, V, or the reversing
pulleys, W and X. These are respectivly connected with the bevel wheels,
W_{1}, and X_{1}, gearing into and placed at opposite sides of the bevel
wheel, Z, on the regulating screw in connection with the fulcrum lever.
When the workman places his foot on the pedal, P, to start the hammer,
he finds his foot within the fork of the lever, U; and by slightly
turning his foot round on his heel he can readily move the forked
lever to right or left, so shifting the small belt on to either of the
reversing pulleys, W or X, and causing the regulating screw, T, to
revolve in either direction. The fulcrum lever is thus caused to move
forward or backward, to give light or heavy blows. By moving the forked
lever into mid position, the small belt is shifted into its usual place
on the loose pulley, V, and the fulcrum remains at rest. To fix the
lightest and heaviest blow required for each kind of work, adjustable
stops are provided, and are mounted on a rod, Y, connected to an arm of
the forked lever. When the nut of the regulating screw comes in contact
with either of the stops, the forked lever is forced into mid position,
in spite of the pressure of the foot of the workman, and thus further
movement of the fulcrum lever, in the direction which it was taking,
is prevented. The movable fulcrum can also be adjusted by hand to any
required blow, when the hammer is stopped, by means of a handle in
connection with the regulating screw.
In conclusion the author wishes to direct attention to the fact, that in
many of our largest manufactories, particularly in the midland counties,
foot and hand labor for forging and stamping is still employed to an
enormous extent. Hundreds of "Olivers," with hammers up to 60 lb. in
weight, are laboriously put in motion by the foot of the workman, at a
speed averaging fifty blows per minute; while large numbers of stamps,
worked by hand and foot, and weighing up to 120 lb., are also employed.
The low first cost of the foot hammers and stamps, combined with the
system of piece work, and the desire of manufacturers to keep their
methods of working secret, have no doubt much to do with the small
amount of progress that has been made; although in a few cases
competition, particularly with the United States of America, has forced
the manufacturer to throw the Oliver and hand-stamp aside, and to employ
steam power hammers and stamps. The writer believes that in connection
with forging and stamping processes there is still a wide and profitable
field for the ingenuity and capital of engineers, who choose to
occupy themselves with this minor, but not the less useful, branch of
mechanics.
* * * * *
THE BICHEROUX SYSTEM OF FURNACES APPLIED TO THE PUDDLING OF IRON.
Since the year 1872, the large iron works at Ougree, near Liege, have
applied the Bicheroux system of furnaces to heating, and, since the
year 1877, to puddling. The results that have been obtained in this
last-named application are so satisfactory that it appears to us to be
of interest to speak of the matter in some detail.
The apparatus, which is shown in the opposite page, consists of three
distinct parts: (1) a gas generator; (2) a mixing chamber into which
the gases and air are drawn by the natural draught, and wherein the
combustion of the gases begins; and (3) a furnace, or laboratory (not
represented in the figure), wherein the combustion is nearly finished,
and wherein take place the different reactions of puddling. These three
parts are given dimensions that vary according to the composition of the
different coals, and they may be made to use any sort of coal, even
the fine and schistose kinds which would not be suitable for ordinary
puddling. The gases and the air necessary for the combustion of these
being brought together at different temperatures, and being drawn into
the mixing chamber through the same chimney, it will be seen that the
dimensions of the flues that conduct them should vary with the kind of
coal used; and the manner in which the gases are brought together is not
a matter of indifference.
[Illustration: THE BICHEROUX SYSTEM OF FURNACE.
Vertical Section, and Horizontal Section through MNOPQR]
The gas generator consists of a hopper, A, into which drops, through
small apertures a, the coal piled up on the platform, D. These apertures
are closed with coal or bricks. The bottom of the generator is formed of
a small standing grate. The coal, on falling upon a mass in a state of
ignition, distills and becomes transformed into coke, which gradually
slides down over a grate to produce afterward, through its own
combustion, a distillation of the coal following it. But as these are
features found in all generators we will not dwell upon them.
The gases that are produced flow through a long horizontal flue, B, into
a vertical conduit, E, into which there debouches at the upper part a
series of small orifices, F, that conduct the air that has been heated.
The gases are inflamed, and traverse the furnace c (not shown in the
cut), from whence they go to the chimney. Before the air is allowed to
reach the intervening chamber it is made to pass into the sole of the
furnace and into the walls of the chamber, so that to the advantage of
having the air heated there is joined the additional one of having those
portions of the furnace cooled that cannot be heated with impunity.
The incompletely burned gases that escape from the furnace are utilized
in heating the boilers of the establishment. The dimensions given these
furnaces vary greatly according to the charge to be used. All the
results at Ougree have been obtained with 400 kilogramme charges,
and the dimensions of the gas generators have been calculated for
Six-Bonniers coal, which does not yield over 20 per cent. of gas.
The advantages of this system, which permits of expediting all the
operations of puddling, are as follows:
1. A notable economy in fuel, both as regards quantity and quality.
2. Economy resulting from diminution in the waste of metal, with a
consequent improvement in the quality of the products obtained.
3. Diminution in cost of repairs.
4. Less rapid wear in the grates.
5. Improvement in the conditions of the work of puddling.
As regards the first of these advantages, it may be stated that the
puddling of ordinary Ougree forge iron, which required with other
furnaces 900 to 1,000 kilogrammes of coal, is now performed with less
than 600 kilogrammes per ton of the iron produced. The puddling of fine
grained iron which required 1,300 to 1,500 kilogrammes of coal is now
done with 800. So much for quantity; as for quality the system presents
also a very marked advantage in that it requires no rolling coal--the
operation of the furnace being just as regular with fine coal, even that
sifted through screens of 0.02 meter.
The second class of advantages naturally results from the almost
complete prevention of access of cold air. The saving in wastage amounts
to 3 or 4 per cent., that is to say, 100 kilogrammes of iron produced is
accompanied by a loss of only 9 to 10 kilogrammes, instead of 13 to 15
as ordinarily reckoned.
The diminution in the cost of repairs is due to the fact that the
furnace doors, of which there are two, permit of easy access to all
parts of the sole; moreover, the coal never coming in contact with the
fire-bridges, the latter last much longer than those in other styles of
furnaces, and can be used for several weeks without the necessity of
the least repair. The reduced wear of the grates results from the low
temperature that can be used in the furnace, and the quantity of clinker
that can be left therein without interfering with its operation, thus
permitting of having the grates always black. These latter in no wise
change, and after five months of work the square bars still preserve
their sharpness of edges.
As for the improvements in the conditions of the work of puddling, it
may be stated that with a uniform price per 100 kilogrammes for all the
furnaces, the laborers working at the gas furnaces can earn 25 to 30 per
cent. more than those working at ordinary furnaces.
* * * * *
GESSNER'S CONTINUOUS CLOTH-PRESSING MACHINE.
It is well known that there are several serious drawbacks in the usual
plan of pressing woolen or worsted cloths and felts with press plates,
press papers, and presses. Three objections of great weight may be
mentioned, and events in Leeds give emphasis to a fourth. The three
objections are--the labor required in setting or folding the cloth,
the expense of the press papers, and the time required. The fourth
objection, about which a dispute has occurred between the press-setters
and the master finishers in Leeds, refers to the inapplicability of the
common system to long lengths. The men object to these on account of
the great labor involved in shifting the heavy mass of cloth and press
plates to and from the presses. A minor drawback of this system is
that it involves the presence of a fold up the middle of the piece. On
account of these drawbacks it has long been understood to be desirable
to expedite the process, and also to dispense with the press papers.
This is the main purpose of the machine we now illustrate in section, in
which the pressing is done continuously by what may be termed a species
of ironing. The machine consists of a central hollow cylinder, C,
three-quarters of the circumference of which is covered by the hollow
boxes, M, heated by steam through the pipes shown, and which are
mounted upon the levers, BB', whose fulcra are at bb. By means of the
hand-wheel, T, and worm-wheel, n, which closes or opens the levers, BB',
the pressure of the boxes upon the central roller may be adjusted at
will, the spring-bolt, F, allowing a certain amount of yield. The faces
of the press-boxes, MM, are covered by a curved sheet of German silver
attached to the point, Y. This sheet takes the place of the press papers
in the ordinary process. The course of the cloth through the machine is
as follows, and is shown by the arrows: It is placed on the bottom board
in front, and in its travel it passes over the rails, O, after which it
is operated on by the brush, Z, leaving which it is conveyed over the
rails, V and I, the rollers, K and P, and thence between the pressing
roller, C, and the German silver press plate covering the heated boxes,
M. Leaving these the piece passes over the roller, P, and is cuttled
down in the bottom board by the cuttling motion, F, or a rolling-up
motion may be applied. The maker states that arrangements for brushing
and steaming may also be attached, so that in one passage through the
machine a piece may be pressed, brushed, and steamed. The speed of the
cylinder may be adjusted according to the quality or requirements of
the goods that are under treatment. At the time of our visit, says the
_Textile Manufacturer_, printed woolen pieces were being pressed at the
rate of about four yards a minute, but higher speeds are often obtained.
Messrs. Taylor, Wordsworth & Co., who have erected many of these
machines in Leeds, Bradford, and Batley, inform us that they find they
are adapted for the pressing of a wide variety of cloths, from Bradford
goods and thin serges to the heavy pieces of Dewsbury and Batley. The
inventor, Ernst Gessner, of Aue, Saxony, adopts an ingenious expedient
for pressing goods with thick lists. He provides an arrangement for
moving the cylinder endwise, according to the different widths of
the pieces to be treated. One list is left outside at the end of the
cylinder, and the other at the opposite end of the pressing boxes. The
machine we saw was 80 in. wide on the roller, and it was one the design
and construction of which undoubtedly do credit to Mr. Gessner.
[Illustration]
* * * * *
IMPROVEMENTS IN WOOLEN CARDING ENGINES.
Mr. Bolette, who has made a name for himself in connection with strap
dividers, has experimented in another direction on the carding engine,
and as his ideas contain some points of novelty we herewith give the
necessary illustrations, so that our readers can judge for themselves as
to the merit of these inventions.
[Illustration: Fig. 1.]
Fig. 1 represents the feeding arrangement. Here the wool is delivered by
the feed rollers, A A, in the usual manner. The longer fibers are then
taken off by a comb, B, and brought forward to the stripper, E, which
transfers them to the roller, H, and thence to the cylinder. The shorter
fibers which are not seized by the comb fall down, but as they drop
they meet a blast of air created by a fan, which throws the lighter and
cleaner parts in a kind of spray upon the roller, L, whence they pass on
to the cylinder, while the dirt and other heavier parts fall downwards
into a box, and are by this means kept off the cylinder. It is evident
that in this arrangement it is not intended to keep the long and the
short fibers separate, but to utilize them all in the formation of
the yarn. The arrangement shown in Fig. 2 refers to the delivery end.
Instead of the sliver being wound upon the roller in the usual way, it
runs upon a sheet of linen, P, as in the case of carding for felt, with
a to-and-fro motion in the direction of the axis of the rollers. In this
way one or more layers of the fleece can be placed on the sheet, which
in that case passes backwards and forwards from roller S to R, and _vice
versa_. It is, in fact, the bat arrangement used for felt, only with
this difference, that the bat is at once rolled up instead of going
through the bat frame. In the manufacture of felt it is of course of
importance to have many very thin layers of fleece superposed over
each other in order to equalize it, and if the same is applied to the
manufacture of cloth it will no doubt give satisfactory results, but may
be rather costly.
[Illustration: Fig. 2.]
* * * * *
NOVELTIES IN RING SPINDLES.
One of the drawbacks of ring spinning is the uneven pull of the
traveler, which is the more difficult to counteract as it is exerted
in jerks at irregular intervals. It is argued that with spindles and
bearings as usually made the spindle is supported firmly in its bearing,
and cannot give in case of such a lateral pull when exerted through the
yarn by the traveler, and the consequence is either a breakage of the
yarn or an uneven thread. Impressed with this idea, and in order to
remedy this defect, an eminent Swiss firm has hit upon the notion of
driving the spindle by friction, and to make it more or less loose in
the bearings, so that in case of an extra pull by the traveler the
spindle can give way a little, and thus prevent the breakage of the
yarn. This idea has been carried out in four different ways, and as this
seems to be an entirely new departure in ring spinning, we give the
illustrations of their construction in detail.
[Illustration: Fig. 1. Fig. 2. Fig. 3. Fig. 4.]
Fig. 1 represents Bourcart's recent arrangement of attaching the thread
guide to the spindle rail and the adjustable spindle. The spindle is
held by the sleeve, g, which latter is screwed into the spindle rail, S,
this being moved by the pinion, a; the collar is elongated upwards in a
cuplike form, c, the better to hold the oil, and keep it from flying;
d is the wharf, which has attached to it the sleeve, m, and which is
situated loosely in the space between the spindle and the footstep, e.
Above the wharf the spindle is hexagonal in shape, and to this part is
attached the friction plate, a. Between the latter and the upper surface
of the wharf a cloth or felt washer is inserted, to act as a brake. The
footstep, e, is filled with oil, in which run the foot of the spindle
and the sleeve m, the latter turning upon a steel ring situated on the
bottom of the footstep. As, thus, the foot of the spindle is quite free,
the upper part of the spindle can give sideways in the direction of any
sudden pull, and the foot of the spindle can follow this motion in the
opposite direction, the collar forming the fulcrum for the spindle. By
this alteration of the vertical position of the spindle into an inclined
one (though ever so trifling), the contact of the friction plate, a, and
the wharf is interrupted, and thus the speed of the spindle reduced.
This will cause less yarn to be wound on, and the pull thus to be
neutralized; but as the wharf keeps turning at the same speed, its
centrifugal force will act again upon the friction plate, and thus bring
the spindle back to its vertical position as soon as the extra drag has
been removed.
In Fig. 2 the footstep, e, has the foot of the spindle more closely
fitting at the bottom, but the upper part of the step opens out
gradually, and forms a conical cavity of a little larger diameter than
the spindle, so that the latter has a considerable play sideways. The
wharf carries in its lower part the sleeve, g, which runs upon a steel
ring as above. The upper surface of the wharf is arched, and upon this
is fitted the correspondingly arched friction plate, a, which latter
is attached to the spindle by a screw. The position of the spindle is
maintained by the collar, m. This collar is loose in the spindle rail,
and only held by the spring, m'. If now, a lateral drag is exerted upon
the upper part of the spindle, the collar car follows the direction of
this drag, and the spindle thus be brought out of the vertical position,
the friction plate slipping at the same time. The force of the spring
conjointly with the centrifugal force will then bring back the spindle
into its normal position as soon as the drag is again even.
Fig. 3 shows a spindle with a very long conical oil vessel, B, resting
upon a disk, e", in cup, e', with a cover, e"'. The wharf, d, is here
situated high up the spindle, has the same sleeve as in the preceding
case, and runs round the bush, g, upon the ring, z. The friction plate
resting upon the wharf is joined to the collar, a, running out into a
cup shape, which is fixed to the spindle, which here has a hexagonal
form. In this case the collar gives with the spindle, which latter
has the necessary play in the long footstep; and as the collar and
friction-plate are one, it is brought back to its normal place by
centrifugal force.
A peculiar arrangement is shown in Fig. 4. Here the ring and traveler,
f, are placed as usual, but the spindle carries at the same time an
inverted flier, t. The spindle turns loosely in the footstep, e, the
oil chamber being carried up to the middle of its height. The wharf
is placed in the same position as in the previous case, having also
a sleeve running in the oil chamber, c, upon a steel ring, z. The
friction-plate a, on the top of the wharf carries the flier, and on its
upper surface is in contact with the inverted cup, a, which is attached
to the spindle by a pin or screw. In order to limit at will the lateral
motion of the spindle there is attached to the latter, between the
footstep and the collar, a split ring, i, which can be closed more
or less by a small set screw. The spindle is thus only held in the
perpendicular position by its own velocity, which will facilitate a
high degree of speed, through the entire absence of all friction in the
bearings, this vertical position being assisted by the friction motion
whenever the spindle has been drawn on one side. Although the notion of
mounting spindles so that they can yield in order to center themselves
is not new, it is evident that considerable ingenuity has been brought
to bear upon the arrangement of the spindles we have described, but we
are not in a position to say to what extent practice has in this case
coincided with theory.--_Textile Manufacturer_.
* * * * *
PHOTO-ENGRAVING ON ZINC OR COPPER.
By LEON VIDAL.
This process is similar in many respects to the one which was some
time ago communicated to the Photographic Society of France by M.
Stronbinsky, of St. Petersburg, but in a much improved and complete
form. An account of it was given by M. Gobert, at the meeting of the
same society, on the 2d December, 1882. The following are the details,
as demonstrated by me at the meeting of the 9th of May last:
Sheets of zinc or of copper of a convenient size are carefully planished
and polished with powdered pumice stone. The sensitive mixture is
composed of:
The whites of four fresh eggs beaten
to a froth......................... 100 parts
Pure bichromate of ammonia......... 2.50 "
Water.............................. 50 "
After this mixture has been carefully filtered through a paper filter, a
few drops of ammonia are added. It will keep good for some time if well
corked and preserved from exposure to the light. Even two months after
being prepared I have found it to be still good; but too large a
quantity should not be prepared at a time, as it does not improve with
keeping.
I find that the dry albumen of commerce will answer as well as the
fresh. In that case I employ the following formula:
Dry albumen from eggs.............. 15 to 20 parts
Water.............................. 100 "
Ammonia bichromate................. 2.50 "
Always add some drops of ammonia, and keep this mixture in a well corked
bottle and in a dark place.
To coat the metal plate, place it on a turning table, to which it is
made fast at the center by a pneumatic holder; to assure the perfect
adhesion of this holder, it is as well to wet the circular elastic ring
of the holder before applying it to the metallic surface. When this is
done, the table may be made to rotate quickly without fear of detaching
the plate by the rapidity of the movement. The plate is placed in a
perfectly horizontal position, where no dust can settle on it; the
mixture is then poured on it, and distributed by means of a triangular
piece of soft paper, so as to cover equally all the parts of the plate.
Care should be taken not to flow too much liquid over the plate, and
when the latter is everywhere coated, the excess is poured off into a
different vessel from that which contains the filtered mixture, or else
into a filter resting on that vessel. The turning table should now be
inverted so that the sensitive surface may be downwards, and it is made
to rotate at first slowly, afterwards more rapidly, so as to make the
film, which should be very thin, quite smooth and even. The whole
operation should be carried out in a subdued light, as too strong a
light would render insoluble the film of bichromated albumen.
When the film is equalized the plate must be detached from the turning
table and placed on a cast iron or tin plate heated to not more than 40 deg.
or 50 deg. C. A gentle heat is quite sufficient to dry the albumen quickly;
a greater heat would spoil it, as it would produce coagulation. So soon
as the film is dry, which will be seen by the iridescent aspect it
assumes, the plate is allowed to cool to the ordinary temperature,
and is then at once exposed either beneath a positive, or beneath an
original drawing the lines of which have been drawn in opaque ink, so as
to completely prevent the luminous rays from passing through them; the
light should only penetrate through the white or transparent ground of
the drawing.
I say a _positive_ because I wish to obtain an engraved plate; if I
wanted to have a plate for typographic printing, I should have to take a
_negative_. After exposure the plate must be at once developed, which is
effected by dissolving in water those parts of the bichromated gelatine
which have been protected from the action of light by the dark spaces
of the cliche; these parts remain soluble, while the others have been
rendered completely insoluble. If the plate were dipped in clear water
it would be difficult to observe the picture coming out, especially on
copper. To overcome this difficulty the water must be tinged with some
aniline color; aniline red or violet, which are soluble in water,
answers the purpose very well. Enough of the dye must be dissolved in
the water to give it a tolerably deep color. So soon as the plate is
plunged into this liquid the albumen not acted on by light is dissolved,
while the insoluble parts are colored by absorbing the dye, so that the
metal is exposed in the lines against a red or violet ground, according
to the color of the dye used.
When the drawing comes out quite perfect, and a complete copy of the
original, the plate with the image on it is allowed to dry either of its
own accord, or by submitting it to a gentle heat. So soon as it is dry
it is etched, and this is done by means of a solution of perchloride
of iron in alcohol. Both alcohol and iron perchloride will coagulate
albumen; their action, therefore, on the image will not be injurious,
since they will harden the remaining albumen still further. But to get
the full benefit of this, the alcohol and the iron perchloride must
both be free from water; it is therefore advisable to use the salt in
crystals which have been thoroughly dried, and the alcohol of a strength
of 95 deg..
The following is the formula:
Perchloride of iron, well dried 50 gr.
Alcohol at 95 deg. 100 "
This solution must be carefully filtered so as to get rid of any deposit
which may form, and must be preserved in a well-corked bottle, when it
will keep for a long time. The plate is first coated with a varnish of
bitumen of Judea on the edges (if those parts are not already covered
with albumen) and on the back, so that the etching liquid can only act
on the lines to be engraved. It is then placed, with the side to be
engraved downwards, in a porcelain basin, into which a sufficient
quantity of the solution of perchloride of iron is poured, and the
liquid is kept stirred so as to renew the portion which touches the
plate; but care must be taken not to touch with the brush the parts
where there is albumen remaining. The length of time that the etching
must be continued depends on the depth required to be given to
the engraving; generally a quarter of an hour will be found to be
sufficient. Should it be thought desirable to extend the action over
half an hour, the lines will be found to have been very deeply engraved.
When the etching is considered to have been pushed far enough, the plate
must be withdrawn from the solution, and washed in plenty of water;
it must then be forcibly rubbed with a cloth so as to remove all the
albumen, and after it has been polished with a little pumice, the
engraving is complete.
It will be seen that this process may be used with advantage instead of
that of photo-engraving with bitumen, in cases where it is not advisable
to use acids. One of my friends, Mr. Fisch, suggests the plan--which
seems to deserve a careful investigation--of combining this process
with that where bitumen is employed; it would be done somewhat in the
following way. The plate of metal would be first coated evenly with
bitumen of Judea on the turning table, and when the bitumen is quite
dry, it should be again coated with albumen in the manner as described
above. In full sunlight the exposure need not exceed a minute in length;
then the plate would be laid in colored water, dried, and immersed in
spirits of turpentine. The latter will dissolve the bitumen in all
the parts where it has been exposed by the removal of the albumen not
rendered insoluble by the action of light. But it remains to be seen
whether the albumen will not be undermined in this method; therefore,
before recommending the process, it ought to be thoroughly studied. The
metal is now exposed in all the parts that have to be etched, while
all the other parts are protected by a layer of bitumen coated with
coagulated albumen. Hence we may employ as mordant water acidulated with
3, 4, or 5 per cent. of nitric acid, according as it is required to have
the plate etched with greater or less vigor.
By following the directions above given, any one wishing to adopt the
process cannot fail of obtaining good results, One of its greatest
advantages is that it is within the reach of every one engaged in
printing operations.--_Photo News_.
* * * * *
MERIDIAN LINE.
[Footnote: From Proceedings of the Association of County Surveyors of
Ohio, Columbus, January, 1882.]
The following process has been used by the undersigned for many years.
The true meridian can thus be found within one minute of arc:
_Directions_.--Nail a slat to the north side of an upper window--the
higher the better. Let it be 25 feet from the ground or more. Let it
project 3 feet. Kear the end suspend a plumb-bob, and have it swing in a
bucket of water. A lamp set in the window will render the upper part of
the string visible. Place a small table or stand about 20 feet south of
the plumb-bob, and on its south edge stick the small blade of a pocket
knife; place the eye close to the blade, and move the stand so as to
bring the blade, string, and polar star into line. Place the table so
that the star shall be seen very near the slat in the window. Let this
be done half an hour before the greatest elongation of the star. Within
four or five minutes after the first alignment the star will have moved
to the east or west of the string. Slip the table or the knife a little
to one side, and align carefully as before. After a few alignments the
star will move along the string--down, if the elongation is west; up, if
east. On the first of June the eastern elongation occurs about half-past
two in the morning, and as daylight comes on shortly after the
observation is completed, I prefer that time of year. The time of
meridian passage or of the elongation can be found in almost any work on
surveying. Of course the observer should choose a calm night.
In the morning the transit can be ranged with the knife blade and
string, and the proper angle turned off to the left, if the elongation
is east; to the right, if west.
Instead of turning off the angle, as above described, I measure 200 or
300 feet northtward, in the direction of the string, and compute the
offset in feet and inches, set a stake in the ground, and drive a tack
in the usual way.
Suppose the distance is 250 feet and the angle 1 deg. 40', then the offset
will be 7,271 feet, or 7 feet 31/4 inches. A minute of arc at the distance
of 250 feet is seven-eighths of an inch; and this is the most accurate
way, for the vernier will not mark so small a space accurately.
ANGLE OF ELONGATION.
This should be computed by the surveyor for each observation. The
distance between the star and the pole is continually diminishing, and
on January 1, 1882, was 1 deg. 18' 48".
There is a slight annual variation in the distance. July 1, 1882, it
will be 1 deg. 19' 20". If from this latter quantity the observer will
subtract 16" for 1883, and the same quantity for each succeeding year
for the next four or five years, no error so great as one-quarter of a
minute will be made in the position of the meridian as determined in the
summer months. If winter observations are made, the distance in January
should be used. The formula for computing the angle of elongation is
easily made by any one understanding spherical trigonometry, and is
this:
R x sin. Polar dist.
--------------------- = sin. of angle of elongation.
cos. lat.
As an example, suppose the time is July, 1882, and the latitude 40 deg..
Then the computation being made, the angle will be found to be 1 deg. 43'
34". A difference of six minutes in the latitude will make less than
10" difference in the angle, as one can see by trial. Any good State
or county map will give the latitude to within one or two miles--or
minutes.
The facts being as here stated, the absurdity of the Ohio law,
concerning the establishment of county meridians, becomes apparent. The
longitude has nothing at all to do With the meridian; and a difference
of _six miles_ in latitude makes no appreciable error in the meridian
established as here suggested, whereas the statute requires the latitude
within _one half a second_, which is _fifty feet_. There are some other
things, besides the ways of Providence, which may be said to be "past
finding out." It is not probable that a surveyor would err so much as
_three_ miles in his latitude, but should he do so, then the error in
his meridian line, resulting from the mistake, will be _five seconds_,
and a line _one mile_ long, run on a course 5" out of the way, will vary
but _an inch and a half_ from the true position. Surveyors well know
that no such accuracy is attainable. R. W. McFARLAND,
* * * * *
ELECTRO-MANIA.
By W. MATTIEU WILLIAMS.
A history of electricity, in order to be complete, must include two
distinct and very different subjects: the history of electrical science,
and a history of electrical exaggerations and delusions. The progress of
the first has been followed by a crop of the second from the time when
Kleist, Muschenbroek, and Cuneus endeavored to bottle the supposed
fluid, and in the course of these attempts stumbled upon the "Leyden
jar."
Dr. Lieberkuhn, of Berlin, describes the startling results which he
obtained, or imagined, "when a nail or a piece of brass wire is put into
a small apothecary's phial and electrified." He says that "if, while it
is electrifying, I put my finger or a piece of gold which I hold in my
hand to the nail, I receive a shock which stuns my arms and shoulders."
At about the same date (the middle of the last century), Muschenbroek
stated, in a letter to Reaumur, that, on taking a shock from a thin
glass bowl, "he felt himself struck in his arms, shoulders, and breast,
so that he lost his breath, and was two days before he recovered from
the effects of the blow and the terror" and that he "would not take a
second shock for the kingdom of France." From the description Of the
apparatus, it is evident that this dreadful shock was no stronger than
many of us have taken scores of times for fun, and have given to
our school-follows when we became the proud possessors of our first
electrical machine.
Conjurers, mountebanks, itinerant quacks, and other adventurers operated
throughout Europe, and were found at every country fair and _fete_
displaying the wonders of the invisible agent by giving shocks and
professing to cure all imaginable ailments.
Then came the discoveries of Galvani and Volta, followed by the
demonstrations of Galvani's nephew Aldini, whereby dead animals were
made to display the movements of life, not only by the electricity of
the Voltaic pile, but, as Aldini especially showed, by a transfer of
this mysterious agency from one animal to another.
According to his experiments (that seem to be forgotten by modern
electricians) the galvanometer of the period, a prepared frog, could be
made to kick by connecting its nerve and muscle with muscle and nerve of
a recently killed ox, with, or without metallic intervention.
Thus arose the dogma which still survives in the advertisements of
electrical quacks, that "electricity is life," and the possibility of
reviving the dead was believed by many. Executed criminals were in
active demand; their bodies were expeditiously transferred from the
gallows or scaffold to the operating table, and their dead limbs were
made to struggle and plunge, their eyeballs to roll, and their features
to perpetrate the most horrible contortions by connecting nerves with
one pole, and muscles with the opposite pole of a battery.
The heart was made to beat, and many men of eminence supposed that if
this could be combined with artificial respiration, and kept up for
awhile, the victim of the hangman might be restored, provided the neck
was not broken. Curious tales were loudly whispered concerning gentle
hangings and strange doings at Dr. Brookes's, in Leicester Square, and
at the Hunterian Museum, in Windmill Street, now flourishing as "The
Cafe de l'Etoile." When a child, I lived about midway between these
celebrated schools of practical anatomy, and well remember the tales of
horror that were recounted concerning them. When Bishop and Williams (no
relation to the writer) were hanged for burking, i.e., murdering people
in order to provide "subjects" for dissection, their bodies were sent to
Windmill Street, and the popular notion was that, being old and faithful
servants of the doctors, they were galvanized to life, and again set up
in their old business.
It is amusing to read some of the treatises on medical galvanism that
were published at about this period, and contrast their positive
statements of cures effected and results anticipated with the position
now attained by electricity as a curative agent.
Then came the brilliant discoveries of Faraday, Ampere, etc.,
demonstrating the relations between electricity and magnetism, and
immediately following them a multitude of patents for electro-motors,
and wild dreams of superseding steam-engines by magneto-electric
machinery.
The following, which I copy from the _Penny Mechanic_, of June 10, 1837,
is curious, and very instructive to those who think of investing in any
of the electric power companies of to-day: "Mr. Thomas Davenport, a
Vermont blacksmith, has discovered a mode of applying magnetic and
electro-magnetic power, which we have good ground for believing will be
of immense importance to the world." This announcement is followed by
reference to Professor Silliman's _American Journal of Science and the
Arts_, for April, 1837, and extracts from American papers, of which the
following is a specimen: "1. We saw a small cylindrical battery, about
nine inches in length, three or four in diameter, produce a magnetic
power of about 300 lb., and which, therefore, we could not move with
our utmost strength. 2. We saw a small wheel, five-and-a-half inches in
diameter, performing more than 600 revolutions in a minute, and lift a
weight of 24 lb. one foot per minute, from the power of a battery of
still smaller dimensions. 3. We saw a model of a locomotive engine
traveling on a circular railroad with immense velocity, and rapidly
ascending an inclined plane of far greater elevation than any hitherto
ascended by steam-power. And these and various other experiments which
we saw, convinced us of the truth of the opinion expressed by Professors
Silliman, Renwick, and others, that the power of machinery may be
increased from this source beyond any assignable limit. It is computed
by these learned men that a circular galvanic battery about three feet
in diameter, with magnets of a proportionable surface, would produce at
least a hundred horse-power; and therefore that two such batteries would
be sufficient to propel ships of the largest class across the Atlantic.
The only materials required to generate and continue this power for
such a voyage would be a few thin sheets of copper and zinc, and a few
gallons of mineral water."
The Faure accumulator is but a very weak affair compared with this, Sir
William Thomson notwithstanding. To render the date of the above fully
appreciable, I may note that three months later the magazine from which
it is quoted was illustrated with a picture of the London and Birmingham
Railway Station displaying a first-class passenger with a box seat on
the roof of the carriage, and followed by an account of the trip to
Boxmoor, the first installment of the London and North-Western Railway.
It tells us that, "the time of starting having arrived, the doors of
the carriages are closed, and, by the assistance of the conductors, the
train is moved on a short distance toward the first bridge, where it
is met by an engine, which conducts it up the inclined plane as far as
Chalk Farm. Between the canal and this spot stands the station-house for
the engines; here, also, are fixed the engines which are to be employed
in drawing the carriages up the inclined plane from Euston Square, by
a rope upwards of a mile in length, the cost of which was upwards of
L400." After describing the next change of engines, in the same matter
of course way as the changing of stage-coach horses, the narrative
proceeds to say that "entering the tunnel from broad daylight to perfect
darkness has an exceedingly novel effect."
I make these parallel quotations for the benefit of those who imagine
that electricity is making such vastly greater strides than other
sources of power. I well remember making this journey to Boxmoor, and
four or five years later traveling on a circular electro-magnetic
railway. Comparing that electric railway with those now exhibiting,
and comparing the Boxmoor trip with the present work of the London and
North-Western Railway, I have no hesitation in affirming that the rate
of progress in electro-locomotion during the last forty years has been
far smaller than that of steam.
The leading fallacy which is urging the electro-maniacs of the present
time to their ruinous investments is the idea that electro-motors
are novelties, and that electric-lighting is in its infancy; while
gas-lighting is regarded as an old, or mature middle-aged business,
and therefore we are to expect a marvelous growth of the infant and no
further progress of the adult.
These excited speculators do not appear to be aware of the fact that
electric-lighting is older than gas-lighting; that Sir Humphry Davy
exhibited the electric light in Albemarle Street, while London was still
dimly lighted by oil-lamps, and long before gas-lighting was attempted
anywhere. The lamp used by Sir Humphry Davy at the Royal Institution, at
the beginning of the present century, was an arrangement of two
carbon pencils, between which was formed the "electric arc" by the
intensely-vivid incandescence and combustion of the particles of carbon
passing between the solid carbon electrodes. The light exhibited by Davy
was incomparably more brilliant than anything that has been lately shown
either in London, or Paris, or at Sydenham. His arc was _four inches
in length_, the carbon pencils were four inches apart, and a broad,
dazzling arch of light bridged the whole space between. The modern arc
lights are but pygmies, mere specks, compared with this; a leap of 1/3
or 1/4 inch constituting their maximum achievement.
Comparing the actual progress of gas and electric lighting, the gas has
achieved by far the greater strides; and this is the case even when we
compare very recent progress.
The improvements connected with gas-making have been steadily
progressive; scarcely a year has passed from the date of Murdoch's
efforts to the present time, without some or many decided steps having
been made. The progress of electric-lighting has been a series of
spasmodic leaps, backward as well as forward.
As an example of stepping backward, I may refer to what the newspapers
have described as the "discoveries" of Mr. Edison, or the use of an
incandescent wire, or stick, or sheet of platinum, or platino-iridium;
or a thread of carbon, of which the "Swan" and other modern lights are
rival modifications.
As far back as 1846 I was engaged in making apparatus and experiments
for the purpose of turning to practical account "King's patent electric
light," the actual inventor of which was a young American, named Starr,
who died in 1847, when about 25 years of age, a victim of overwork
and disappointment in his efforts to perfect this invention and a
magneto-electric machine, intended to supply the power in accordance
with some of the "latest improvements" of 1881 and 1882.
I had a share in this venture, and was very enthusiastic until after I
had become practically acquainted with the subject. We had no difficulty
in obtaining a splendid and perfectly steady light, better than any that
are shown at the Crystal Palace.
We used platinum, and alloys of platinum and iridium, abandoned them as
Edison did more than thirty years later, and then tried a multitude of
forms of carbon, including that which constitutes the last "discovery"
of Mr. Edison, viz., burnt cane. Starr tried this on theoretical
grounds, because cane being coated with silica, he predicted that by
charring it we should obtain a more compact stick or thread, as the
fusion of the silica would hold the carbon particles together. He
finally abandoned this and all the rest in favor of the hard deposit of
carbon which lines the inside of gas-retorts, some specimens of which we
found to be so hard that we required a lapidary's wheel to cut them into
the thin sticks.
Our final wick was a piece of this of square section, and about 1/8 of
an inch across each way. It was mounted between two forceps--one holding
each end, and thus leaving a clear half-inch between. The forceps were
soldered to platinum wires, one of which passed upward through the top
of the barometer tube, expanded into a lamp glass at its upper part.
This wire was sealed to the glass as it passed through. The lower wire
passed down the middle of the tube.
The tube was filled with mercury and inverted over a cup of mercury.
Being 30 inches long up to the bottom of the expanded portion, or lamp
globe, the mercury fell below this and left a Torricellian vacuum there.
One pole of the battery, or dynamo-machine, was connected with the
mercury in the cup, and the other with the upper wire. The stick of
carbon glowed brilliantly, and with perfect steadiness.
I subsequently exhibited this apparatus in the Town-hall of Birmingham,
and many times at the Midland Institute. The only scientific difficulty
connected with this arrangement was that due to a slight volatilization
of the carbon, and its deposition as a brown film upon the lamp glass;
but this difficulty is not insuperable.--_Knowledge_.
* * * * *
ACTION OF MAGNETS UPON THE VOLTAIC ARC.
The action of magnets upon the voltaic arc has been known for a long
time past. Davy even succeeded in influencing the latter powerfully
enough in this way to divide it, and since his time Messrs. Grove and
Quet have studied the effect under different conditions. In 1859, I
myself undertook numerous researches on this subject, and experimented
on the induction spark of the Ruhmkorff coil, the results of these
researches having been published in the last two editions of my notes on
the Ruhmkorff apparatus.
[Illustration: FIG. 1]
These researches were summed up in the journal _La Lumiere Electrique_
for June 15, 1879. Recently, Mr. Pilleux has addressed to us some new
experiments on the same subject, made on the voltaic arc produced by a
De Meritens alternating current machine. Naturally, he has found the
same phenomena that I had made known; but he thinks that these new
researches are worthy of interest by reason of the nature of the arc in
which he experimented, and which, according to him, is of a different
nature from all those on which, up to the present time, experiments have
been made. Such a distinction as this, however, merits a discussion.
With the induction spark, magnets have an action only on the aureola
which accompanies the line of fire of the static discharge; and this
aureola, being only a sort of sheath of heated air containing many
particles of metal derived from the rheophores, represents exactly the
voltaic arc.
[Illustration: FIG. 2]
Moreover, although the induced currents developed in the bobbin are
alternately of opposite direction, the galvanometer shows that the
currents that traverse the break are of the same direction, and that
these are direct ones. The reversed currents are, then, arrested during
their passage; and, in order to collect them, it becomes necessary to
considerably diminish the gaseous pressure of the aeriform conductor
interposed in the discharge; to increase its conductivity; or to open to
the current a very resistant metallic derivation. By this latter means,
I have succeeded in isolating, one from the other, in two different
circuits, the direct induced currents and the reversed induced ones.
As only direct currents can, in air at a normal pressure, traverse
the break through which the induction spark passes, the aureola that
surrounds it may be considered as being exactly in the same conditions
as a voltaic arc, and, consequently, as representing an extensible
conductor traversed by a current flowing in a definite direction. Such
a conductor is consequently susceptible of being influenced by all the
external reactions that can be exerted upon a current; only, by reason
of its mobility, the conductor may possibly give way to the action
exerted upon the current traversing it, and undergo deformations that
are in relation with the laws of Ampere. It is in this manner that I
have explained the different forms that the aureola of the induction
spark assumes when it is submitted to the action of a magnet in the
direction of its axial line, or in that of its equatorial line, or
perpendicular to these latter, or upon the magnetic poles themselves.
Experiments of a very definite kind have not yet been made as to the
nature of the arc produced by induced currents developed in alternating
current machines; but, from the experiments made with electric candles,
we are forced to admit that the current reacts as if it were alternately
reversed through the arc, since the carbons are used up to an equal
degree; and, moreover, Mr. Pilleux's experiments show that effects
analogous to those of induction coils are produced by the reaction of
magnets upon the arc. There is, then, here a doubtful point that it
would be interesting to clear up; and we believe that it is consequently
proper to introduce in this place Mr. Pilleux's note:
"Having at my disposal," says he, "a powerful vertical voltaic arc of 12
centimeters in length, kept up by alternately reversed currents, and one
of the most powerful permanent magnets that Mr. De Meritens employs for
magneto-electric machines, I have been enabled to make the following
experiments:
"1. When I caused one of the poles of my magnet to slowly approach the
voltaic arc, I ascertained that, at a distance of 10 centimeters, the
arc became flattened so as to assume the appearance of those gas jets
called 'butterfly.' The plane of the 'butterfly' was parallel with the
pole that I presented, or, in other words, with the section of the
magnet. At the same time, the arc began to emit a strident noise, which
became deafening when the pole of the magnet was brought to within a
distance of about 2 millimeters. At this moment, the butterfly form
produced by the arc was _greatly spread out, and reduced to the
thickness of a sheet of paper_; and then it burst with violence, and
projected to a distance a great number of particles of incandescent
carbon.
"2. The magnet employed being a horseshoe one, when I directed it
laterally so as to present successively, now the north and then the
south pole to the arc, the 'butterfly' pivoted upon itself so as not to
present the same surface to each pole of the magnet."
By referring to the accompanying figure, which we extract from our note
on the Ruhmkorff apparatus, it will be seen that the aureola which
developed as a circular film from right to left at D, on the north pole
of the magnet, N.S. (Fig. 1), projected itself in an opposite direction
at C, upon the south pole, S, of the same magnet; but, between the two
poles, these two contrary actions being obliged to unite, they gave rise
in doing so to a very characteristic helicoid spiral whose direction
depended upon that of the current of discharge through the aureola,
or upon the polarity of the magnetic poles. On the contrary, when the
discharge took place in the direction of the equatorial line, as in Fig.
2, the circular film developed itself in the plane of the neutral line
above or below the line of discharge, according to the direction of the
current and the magnetic polarity of the magnet.
There is, then, between Mr. Pilleux's experiments and my own so great an
analogy that we might draw the deduction therefrom that induced currents
in alternating machines have, like those of the Ruhmkorff coil, a
definite direction, which would be that of currents having the greatest
tension, that is to say, that of direct currents. This hypothesis seems
to us the more plausible in that Mr. J. Van Malderem has demonstrated
that the attraction of solenoids with the currents, not straight,
of magneto-electric machines is almost as great as that of the same
solenoids with straight currents; and it is very likely that the
difference which may then exist should be so much the less in proportion
as the induced currents have more tension. We might, then, perhaps
explain the different effects of the wear of the carbons serving as
rheophores, according as the currents are continuous or alternating, by
the different calorific effects produced on these carbons, and by the
effects of electric conveyance which are a consequence of the passage of
the current through the arc.
We know that with continuous currents the positive carbon possesses a
much higher temperature than the negative, and that its wear is about
twice greater than that of the latter. But such greater wear of the
positive carbon is especially due to the fact that combustion is greater
on it than on the negative, and also to the fact that the carbonaceous
particles carried along by the current to the positive pole are
deposited in part upon the other pole. Supposing that these polarities
of the carbons were being constantly alternately reversed, the effects
might be symmetrical from all quarters, although the only current
traversing the break were of the same direction; for, admitting that the
reverse currents could not traverse the break, they would exist none the
less for all that, and they might give rise (as has been demonstrated
by Mr. Gaugain with regard to the discharges of the induction spark
intercepted by the insulating plate of a condenser) to return discharges
through the generator, which would then have, in the metallic part of
the circuit, the same direction as the direct currents succeeding,
although they had momentarily brought about opposite polarities in the
electrodes. What might make us suppose such an interpretation of the
phenomenon to have its _raison d'etre_, is that with the induced
currents of the Ruhmkorff coil, it is not the positive pole that is
the hottest, but rather the negative; from whence we might draw the
deduction that it is not so much the direction of the current that
determines the calorific effect in the electrodes, as the conditions of
such current with respect to the generator. I should not be
surprised, then, if, in the arc formed by the alternating currents of
magneto-electric machines, there should pass only one current of the
same direction, and which would be the one formed by the superposition
of direct currents, and if the reverse currents should cause return
discharges in the midst of the generating bobbins at the moment the
direct currents were generated.--_Th. Du Moncel_.
* * * * *
VOLCKMAR'S SECONDARY BATTERIES.
The inventive genius of the country is now directed to these important
accessories of electric enterprise, and no wonder, for as far as can at
present be seen, the secret of electric motion lies in these secondary
batteries. Among other contributions of this kind is the following, by
Ernest Volckmar, electrician, Paris:
The object of this invention is to render unnecessary the use in
secondary batteries of a porous pot which creates useless resistance
to the electric current, and to store in an apparatus of comparatively
small weight and bulk considerable electric force. To this end two
reticulated or perforated plates of lead of similar proportions are
prepared, and their interstices are filled with granules or filaments of
lead, by preference chemically pure. These plates are then submitted to
pressure, and placed together, with strips of nonconducting material
interposed between them, in a suitable vessel containing a bath of
acidulated water. The plates being connected with wires from an electric
generator are brought for a while under the action of the current, to
peroxidize and reduce the whole of the finely divided lead exposed to
the acidulated water. The secondary battery is then complete. It will be
understood that any number of these pairs of plates may be combined to
form a secondary battery, their number being determined by the amount
of storage required. The perforated plates of lead may be prepared by
drilling, casting, or in other convenient manner, but the apertures, of
whatever form, should be placed as closely together as possible, and
the finely divided lead to be peroxidized is pressed into the cells or
cavities so as to fill their interiors only.
* * * * *
THE MINERALOGICAL LOCALITIES IN AND AROUND NEW YORK CITY, AND THE
MINERALS OCCURRING THEREIN.
By NELSON H. DARTON.
There will be many persons in the city of New York and its suburbs who
will not have the time or facilities for leaving town during the summer,
to spend a part of their time enjoying the country, but would have
sufficient time to take occasional recreation for short periods. I have
sought by this paper to show a pleasurable, and at the same time very
instructive use for the time of this latter class, and that is in
mineralogy. In the surrounding parts of New York are many mineralogical
localities, known to no others than a few professional mineralogists,
etc., and from which an excellent assortment of minerals may be
obtained, which would well grace a cabinet and afford considerable
instruction and entertainment to their owner and friends, besides acting
as an incentive to a further study of this and the other sciences. These
localities which I will discuss are all within an hour's ride from New
York, and the expenses inside of a half dollar, and generally very much
less. I could detail many other places further off, but will reserve
that for another paper.
The course which I will pursue in my explanations I have purposely made
very simple, avoiding--or when using, explaining--all technical terms.
The apparatus and tests noticed are of the most rudimentary style
consistent with that which is necessary to attain the simple purpose of
distinguishment, and altogether I have prepared this paper for those
having at the present time little or no knowledge or practice in
mineralogy, while those having it can be led perhaps by the details of
the localities noticed. Another reason why I have written so in detail
of this last subject is, because the experiences of most amateur
mineralogists are generally so very discouraging in their endeavors to
find the minerals, and there is everything in giving a good start
to properly fix the interest on the subject. The reason of these
discouragements is simple, and generally because they do not know the
portion of the locality, say, for instance, a certain township, in which
the minerals occur. And if they do succeed in finding this, it is seldom
that the portion in which the mineral occurs, which is generally some
small inconspicuous vein or fissure, is found; and even in this it
is generally difficult to recognize and isolate the mineral from the
extraneous matter holding it. As an instance of this I might cite thus:
Dana, in his text book on mineralogy, will mention the locality for
a certain species, as Bergen Hill--say for this instance, dogtooth
calespar. When we consider that Bergen Hill, in the limited sense of the
expression, is ten miles long and fully one mile wide, and as the rock
outcrops nearly all over it, and it is also covered with quarries,
cuttings, etc., it may be seen that this direction is rather indefinite.
To the professional mineralogist it is but an index, however, and he
may consult the authority it is quoted from--the _American Journal of
Science_, etc.--and thus find the part referred to, or by consulting
other mineralogists who happen to know. Again, the person having found
by inquiry that the part referred to is the Pennsylvania Railroad, and
as this is fully a mile long and interspersed with various prominent
looking, but veins of a mineral of little value, at any rate not the one
in question, they are few who could suppose that it occurred in that.
Apparently a vein of it would not be noticed at all from the surrounding
rock of gravelly earth, but there it is, and in a vein of chlorite. This
is so throughout the long and more or less complete stated lists of
mineralogical localities. Thus I will, in describing the mineral, after
explaining the conditions under which it occurs, give almost the
exact spot where I have found the same mineral myself, and have left
sufficiently fine specimens to carry away, and thus no time will be lost
in going over fruitless ground, and further, this paper is written up to
the date given at its end, insuring a necessary presence of them.
In order that one not familiar with mineral specimens should not carry
off from the various localities a variety of worthless stones, etc.,
which are frequently more or less attractive to an inexperienced eye,
the following hints may be salutary.
There are the varieties of three minerals, which are very commonly met
with in greater or less abundance in mineralogical trips: they are of
calcite, steatite, and quartz. They occur in so many modifications of
form, color, and condition that one might speedily form a cabinet of
these, if they were taken when met with, and imagine it to be of great
value. The first of these is calcite. It occurs as marble, limestone;
calcspar, dogtooth spar, nail head spar, stalactites, and a number of
other forms, which are only valuable when occurring in perfect crystals
or uniquely set upon the rock holding it. The calcspar is extremely
abundant at Bergen Hill, where it might be mistaken for many of the
other minerals which I describe as occurring there, and even in
preference to them, to one's great chagrin upon arriving home and
testing it, to find that it is nothing but calcite. In order to avoid
this and distinguish this mineral on the field, it should be tested with
a single drop of acid, which on coming in contact with it bubbles up or
effervesces like soda water, seidlitz powder, etc., while it does not do
so with any of the minerals occurring in the same locality. This acid
is prepared for use as follows: about twenty drops of muriatic acid are
procured from a druggist in a half-ounce bottle, which is then filled up
with water and kept tightly corked. It is applied by taking a drop out
on a wisp of broom or a small minim dropper, which may be obtained at
the druggist's also. I do not say that in every case this mineral should
be rejected, because it is frequently very beautiful and worthy of place
in a cabinet, but should be kept only under the conditions mentioned
further on in this paper, under the head of "Calcite in Weehawken
Tunnel."
The next mineral abundant in so many forms is quartz, and is not so
readily distinguished as calcite. It is found of every color, shape,
etc., possible, and that which is found in any of the localities I am
about to describe, with the exception of fine crystals on Staten Island,
are of no value and may be rejected, unless answering in detail to the
description given under Staten Island. The method of distinguishing the
quartz is by its hardness, which is generally so great that it cannot be
scratched by the point of a knife, or at least with great difficulty,
and a fragment of it will scratch glass readily; thus it is
distinguished from the other minerals occurring in the localities
discussed in this paper.
The other minerals so common are the varieties of steatite. This is
especially so at Bergen Hill and Staten Island. They occur in amorphous
masses generally, and may be distinguished by being so soft as to be
readily cut by the finger nail. I will detail further upon the soapstone
forms in discussing the localities on Staten Island, and the chloritic
form under the head of "Weehawken Tunnel." The surest method of avoiding
these and recognizing the others by their appearance, which is generally
the only guide used by a professional mineralogist, is to copy off the
lists of the various minerals I describe, and, by visiting the American
Museum of Natural History on any week day except Mondays and Tuesdays,
one may see and become familiar with the minerals they are going
in quest of, besides others in the cases. This method is much more
satisfactory than printed descriptions, and saves the labor of many of
the distinguishing manipulations I am about to describe, besides saving
the trouble of bringing inferior specimens of the minerals home.
In going forth on a trip one should be provided with a mineralogical
hammer, or one answering its purpose, and a cold chisel with which to
detach or trim the minerals from adhering rocks, the bottle of acid
before referred to, and a three cornered file for testing hardness,
as explained further on. As I noticed before, the better plan of
distinguishing a mineral is by being familiar with its appearance, but
as this is generally impracticable, I will detail the modes used in
lieu of this to be applied on bringing the minerals home. These
distinguishments depend on difference in specific gravity, hardness,
solubility in hot acids, and the action of high heat. I will explain the
application of each one separately, commencing with--
_The Specific Gravity_.--In ascertaining the specific gravity the
following apparatus is necessary: a small pair of hand scales with a set
of weights, from one grain to one ounce. These can be procured from the
apparatus maker, the scales for about fifty cents, and the weights for
not much over the same amount. The scales are prepared for this work by
cutting two small holes in one of the scale pans, near together, with
a pointed piece of metal, and tying a piece of silk thread about eight
inches long into these. In a loop at the end of this thread the mineral
to be examined is suspended. It should be a pure representative of the
mineral it is taken from, should weigh about from one hundred grains to
an ounce, and be quite dry and free from dirt. If the piece of mineral
obtained is very large, this sized portion may be often taken from it
without injury; but it will not do to mar the beauty of a mineral to
ascertain its specific gravity, and it is generally only applicable
when a small piece is at hand. With more weights, however, a piece of a
quarter pound weight may be taken if necessary. The mineral is tied into
the loop and weighed, the weight being set down in the note book, either
in grains or decimal parts of an ounce. Call this result A. It is then
weighed in some water held in a vessel containing about a quart, taking
care while weighing it that it is entirely immersed, but at the same
time does not touch either the sides or bottom. Both weighings should
be accurate to a grain. This result we call B. The specific gravity is
found by subtracting B from A, and dividing A by the remainder. For
instance, if the mineral weighed eight hundred grains when weighed in
the air, and in the water six hundred, giving us the equation: 800
/ (800 - 600) = sp. gr., or 4, which is the specific gravity of
the mineral. If the mineral whose specific gravity is sought is an
incrustation on a rock, or a mixture of a number of minerals, or would
break to pieces in the water, the specific gravity is by this method of
course unattainable, and other data must be used.
_The Comparative Hardness_.--The next characteristic of the mineral to
be ascertained is the comparative hardness. In mineralogy there is a
scale fixed for comparison, from 1 to 10, 10 being the hardest, the
diamond, and Number 1 the soft soapstone. These and the intermediate
minerals fixed upon the scale are generally inaccessible to those who
may use the contents of this paper, and I will give some more familiar
materials for comparison. 8, 9, and 10 are the topaz, sapphire, and
diamond respectively, and as these and minerals of similar hardness will
probably not be found in any of the localities of which I make mention,
we need not become accustomed to them for the present. 7 is of
sufficient hardness to scratch glass, and is also not to be cut with the
file before mentioned, which is used for these determinations. 6 is
of the hardness of ordinary French glass. 5 is about the hardness of
horse-shoe or similar iron; 4 of the brown stone (sandstone) of which
the fronts of many city buildings, etc., are built; 3 of marble; 2 of
alabaster; and 1 as French chalk, or so soft as to be readily cut with
the finger nail. The method of using and applying these comparisons is
by having the above matters at hand, and compare them by the relative
ease with which they can be cut by running the edge of the file over
their surface. One will soon become familiar with the scale, and it
may of course then be discarded. As it is one of the most important
characteristics of some of the minerals, it should be carefully
executed, and the result carefully considered. It is of course
inapplicable under those conditions with minerals that are in very small
crystals or in a fibrous condition.
_Action of Hot Acids_.--This very important test is never, like the
above, applicable upon the field, but applied when home is reached.
From the body of the mineral as pure and clean as possible a portion is
chipped, about the size of a small pea; this is wrapped in a piece of
stiff wrapping paper, and after placing it in contact with a solid body,
crushed finally by a blow from the hammer. A pinch of the powder so
obtained is taken up on the point of a penknife, and transferred into
a test tube. Two or more of these should be provided, about six inches
long. They may be obtained in the apparatus shop for a trifle. Some
hydrochloric, or, as it is generally called, muriatic acid, is poured
upon it to the depth of about three quarters of an inch; the tube is
then placed in some boiling water heated over a lamp in a tinned or
other vessel, and allowed to boil for from ten to fifteen minutes;
the tube is then removed and its contents allowed to cool, and then
examined. If the powder has all disappeared, we term the mineral
"soluble;" if more or less is dissolved, "partly soluble;" if none,
"insoluble;" and if the contents of the tube are of a solid transparent
mass like jelly, "gelatinous;" while if transparent gelatinous flakes
are left, it is so termed. As this method of distinguishment is always
applicable, it is very important, and its detail and result should be
carefully noticed. Care should be taken that only a small portion of
the mineral is used, and also but little acid; the action should be
observed, and is frequently a characteristic, in the case with calcspar,
which effervesces while dissolving. The acid used is hydrochloric at
first, and then, if the mineral cannot he recognized, the same treatment
may be repeated using nitric acid. Both of these acids should be at hand
and two ounces are generally sufficient.
_Action of Heat_.--This is, perhaps, the most important characteristic,
and, when taken with the preceding data, will identify any of the
minerals found in any one locality, which I will describe, from each
other. The heat is applied to the mineral by means of a candle and
blowpipe. A thick wax candle answers well, and an ordinary japanned tin
blowpipe, costing twenty cents, will serve the purpose. The substance
to be examined is held on a loop of platinum wire about one inch to the
left and just below the top of the wick, which is bent toward it. Here
it is steadily held, as is shown in Fig. 1, and the flame of the candle
bent over upon it, and the heat intensified by blowing a steady and
strong current of air across it by means of the blowpipe held in the
mouth and supported by the right hand, whose elbow is resting upon the
table. The current of air is difficult to keep up by one unaccustomed to
the blowpipe, the skill of using which is readily obtained; it consists
in breathing through the nostrils, while the air is forced out by
pressure on the air held by the inflated cheeks, and not from the lungs.
This can be practiced while not using the blow-pipe, and may readily
be accomplished by one's keeping his cheeks distended with air and
breathing at the same time.
This heat is steadily applied until the splinter of mineral has been
kept at a high red heat for a sufficient length of time to convince one
of what it may do, as fuse or not, or on the edges. The first two
are evident, as when it fuses it runs into a globule; the last, by
inspecting it before and after the heating with a magnifying glass;
sometimes it froths up when heated, and is then said to "intumesce;" or,
if it flies to fragments, "decrepitates." Upon the first it is further
heated; but in the latter case, a new splinter of mineral must be broken
off from the mass and heated upon the wire very cautiously until quite
hot, when it may then be readily heated further without fear of loss.
For holding the splinter of mineral, which should well represent the
mass and be quite small, is a three-inch length of platinum wire of the
thickness of a cambric-needle; this may be bought for about ten cents at
the apparatus shop. The ends should be looped, as is shown in Fig. 2,
and the mineral placed in the loop.
Sometimes a mineral has to be fused with borax, as I mention further
on in my tables. This is done by heating the wire-loop to redness, and
plunging it into some borax; what adheres is fused upon it by heating.
Some more is accumulated in the same manner, until the loop is filled
with a fair-sized globule. A small quantity of the mineral, which had
been crushed as for the acid test, is caused to adhere to it while it is
molten, and then the heat of the blast directed upon it for some time
until either the small fragments of mineral dissolve, or positively
refuse to do so. After cooling, the aspect of the globule is noticed as
to color, transparency, etc. Care must be taken that too large an amount
of the mineral is not taken, a very minute amount being sufficient.
I trust by the use of these distinguishing reactions one will be able
to recognize by the tables to be given the name of the mineral in hand,
especially as they are from certain parts, where all the minerals
occurring therein are known to us; and I have worded the characteristics
so that they will serve to isolate from all that possibly could be found
in that locality.
The first general locality is Bergen Hill, New Jersey. This comprises
the range of bluffs of trap rock commencing at Bergen Point and running
up behind Jersey City and Hoboken, etc., to the part opposite about
Thirtieth Street, New York, where it comes close to the river, and from
there along the river to the north for a long distance, known as the
Palisades. It is about a mile wide on an average, and from a few feet to
about two hundred feet in height. The mineralogical localities in and
upon it are at the following parts, commencing at the south: First
Pennsylvania Railroad cuts where the mining operations are just about
completed; then the Erie Tunnel, in which the specimens that first made
Bergen Hill noted as a mineralogical locality, and whose equals have not
since been procured, were found, but which is now inaccessible to the
general public. Further north is the Morris and Essex Tunnel, in which
many fine specimens were secured, and is also inaccessible; and last,
but far from being least, is the Ontario Tunnel at Weehawken; and, as
it is the only practicable part besides the Pennsylvania Railroad and a
number of surface outcrops which I will mention, I will commence with
that.
_The Weehawken Tunnel_--This tunnel is now being cut through the
trap-rock for the New York, Ontario, and Western Railroad, and will
be completed in a few months, but will, probably, be available as a
mineralogical locality for a year to come. It is located about half a
mile south of the Weehawken Ferry from Forty-second Street, New York
city, and the place where to climb upon the hill to get to the shafts
leading to it is made prominent by the large body of light-colored rock
on the dump, a few rods north of where the east entrance is to be. The
western end is in the village of New Durham, on the New Jersey Northern
Railroad, and recognized by the immense earth excavations. A pass is
necessary to gain admittance down the shafts, and this can be procured
from the office of the company, between the third and fourth shafts to
the tunnel, in the grocery and provision store just to the north of
the tramway connecting the shafts on the surface. As it will not be
necessary to go down in any of the shafts besides the first and second
in order to fulfill the objects of this paper, no difficulty need be
encountered in procuring the pass if this is stated.
These two shafts are about eight hundred feet apart and one hundred and
seventy feet deep. A platform elevator is the mode of access to the
tunneled portion below, and a free shower-bath is included in the
descent; consequently, a rubber-coat and water tight boots are
necessary. A pair of overalls should be worn if one is to engage in
any active exploration below; candles should also be provided, as the
electric lights, at the face of the headings, give but little light, and
remind one very forcibly of a dim flash light with a foliaged tree in
front of it. The electric wires for supplying these arrangements run
along the north side of the tunnel for those on the east headings, and
on the south side for the west. They are excellent things to keep clear
of, as they have sufficient current passing through them to knock one
down; thus their position can be readily ascertained.
_Modes of Occurrence of the Minerals_.--In general, the greater number
of the specimens which are to be found in the tunnel occur in veins
generally perpendicular, and with other minerals of little or no value,
as calcite, chlorite, and imperfect crystals of the same mineral. A
few occur in nodules inclosed in the solid body of rock, and in which
condition they are seldom of value. The greater abundance are in the
veins of the dark-green soft chlorite, and some few in horizontal beds.
The minerals are found in the first condition by examining all the veins
running from floor to ceiling of the tunnel. The ores of calcite first
mentioned are very conspicuous, they being white in the dense black
rock. They may be chipped from, as there are about thirty or forty of
them exposed in each shaft, and the character of the minerals examined
to see if anything but calcite is in it. This is ascertained by a drop
of acid, as explained before, and by the descriptions given further on.
The veins of chlorite are not so conspicuous, being of a dark-green
color; but by probing along the walls with a stick or hammer, they may
be recognized by their softness, or by its dull glistening appearance.
They are comparatively few, but from an inch to three feet wide; and
minerals are found by digging it out with a stick or a three-foot drill,
to be had at the headings. Where the most minerals occur in the chlorite
is when plenty of veins of calcite are in its vicinity, and its edges
near the trap are dry and crumbly. It is here where the minerals are
found in this crumbly chlorite, and generally in geodes--that is, the
faces of the minerals all point inward, formerly a spherical mass--rough
and uncouth on the outside, and from half an inch to nearly a foot in
diameter. These are valuable finds, and well worth digging for. The beds
of minerals generally are of but one species, and will be mentioned
under the head of the minerals occurring in them. Besides, in the tunnel
there are generally more or less perfect minerals upon the main dump
over the edge of the bluff toward the river. Here many specimens that
have escaped the eyes of the miners may be found among the loose rock,
being constantly strewn out by the incline of the bed; in fact, this is
the only place in which quite a number of the incident minerals may be
found; but I will not linger longer on this, as I shall refer to it
under the minerals individually.
The minerals occurring at the tunnel are as follows, with their
descriptions and locations in the order of their greatest abundance:
_Calcite_.--This mineral occurs in great abundance in and about the
tunnel, and from all the shafts. There are two forms occurring there,
the most abundant of which is the rhombohedral, after Fig. 3. It can
generally be obtained, however, in excellent crystals, which, although
perfect in form, are opaque, but often large and beautiful. It is always
packed with a thousand or its multiple of other crystals into veins of a
few inches thick; and crystals are obtained by carefully breaking with
edge of the cold chisel these masses down to the fundamental form shown.
As the masses are never secured by the miners, they can always be picked
from the piles of _debris_ around the shafts and the dumps, and afford
some little instruction as to the manner in which a mineral is built up
by crystallization, and may be subdivided by cleavage to a crystal of
the same shape exactly, but infinitesimally small. A crystal to be worth
preserving should be about an inch in diameter, and as transparent as is
attainable.
Another form of calcite which is to be sparingly found is what is called
dogtooth spar, having the form shown in Fig. 4. They occur in clear
wine-yellow-colored crystals, from a quarter to half an inch in length;
they occur in the chlorite in geodes of variable sizes, but generally
two and a half inches in diameter, and which, when carefully broken in
half, showed beautiful grottoes of these crystals. The few of these that
I have found were in the four-foot vein of chlorite down the Shaft No.
1, to the west of the shaft about one hundred and fifty feet, and on
the south wall; it may be readily found by probing for it, and then the
geodes by digging in. There need be no difficulty in finding this vein
if these conditions are carefully considered, or if one of the miners
be asked as to the soft vein. Both these forms of calcite may be
distinguished from the other minerals by first effervescing on coming
in contact with the acids; second, by glowing with an intense (almost
unbearably so) light when heated with the blowpipe, but not fusing.
Their specific gravity is 2.6, or near it, and hardness about 3, or
equal to ordinary unpolished white marble.
_Natrolite_.--The finest specimens of this mineral that have ever been
found in Bergen Hill were taken from a bed of it in this tunnel, having
in its original form, before it was cut out by the tunnel passing
through, over one hundred square feet, and from one-half to two and a
half and even three inches in thickness; it was in all possible shapes
and forms--all extremely rare and beautiful. A large part of one end
of this bed still remains, and, by careful cutting, fine masses may be
obtained. This bed may be readily found; it is nearly horizontal, and in
its center about four feet from the floor of the tunnel, and about half
an inch thick. It is down Shaft No. 2, on the north wall, and commences
about eighty feet from the shaft. It is cut into in some places, but
there is plenty more left, and can be obtained by cutting the rock
above it and easing it out by means of the blade of a knife or similar
instrument. This natrolite is a grouping of very small but perfect
crystals, having the forms shown in Fig. 5; they are from a quarter to
an inch long, and, if not perfectly transparent, are of a pure white
color; they may be readily recognized by their form, and occurring in
this bed. Its hardness, which is seldom to be ascertained owing to the
delicacy of the crystals, is about 5, and the specific gravity 2.2.
This is readily found, but is no distinction; its reaction before the
blowpipe, however, is characteristic, it readily fusing to a transparent
globule, clear and glassy, and by forming a jelly when heated with
acids. The bed holding the upright crystals is also natrolite in
confused matted masses. This mineral has also been found in other parts
of the shaft, but only in small druses. There is a prospect at present
that another bed will be uncovered soon, and some more fine specimens to
be easily obtained.
_Pectolite_, or as it is termed by the miners, "silky spar."--This
mineral is quite abundant and in fine masses, not of the great beauty
and size of those taken from the Erie Tunnel, but still of great
uniqueness. The mineral is recognized by its peculiar appearance, as
is shown in Fig. 6, where it may be seen that it is in groups of
fine delicate fibers about an inch long, diverging from a point into
fan-shaped groups. The fibers are very tightly packed together, as are
also the groups; they are very tough individually, and have a hardness
of 4, and a specific gravity of about 2.5. It gelatinizes on boiling
with acid, and a fragment may be readily fused in the blowpipe flame,
yielding a transparent globule. The appearance is the most striking
characteristic, and at once distinguishes this mineral from any of the
others occurring in this locality. Considerable quantities of pectolite
may generally be found on the dump, but also in Shaft No. 1, and
especially No. 2. The veins of it are difficult to distinguish from the
calcite, as they are almost identical in color, and many of the calcite
veins are partly of pectolite--in fact, every third or fourth vein will
contain more or less of it. There is, however, a very fine vein of
pectolite about twenty-five feet further east from the natrolite bed; it
runs from the floor to ceiling, and is about two inches in thickness;
some specimens of which I took from these were unusually unique in both
size and appearance. It makes a very handsome specimen for the cabinet,
and should be carefully trimmed to show the characteristics of the
mineral.
_Datholite_.--This mineral has been found very frequently in the tunnel,
it occurring in pockets in the softer trap near the chlorite, and also
in the latter, generally at a depth of one hundred and fifty feet from
the surface, and consequently near the ceiling of the tunnel. All that
has been found of any great beauty has been in the western end of the
Shaft No. 1 and the eastern of Shaft No. 2, where the trap is quite
soft; here it is found nearly every day in greater or less quantity, and
from this some may generally be found on the dump, or, in the vein
of chlorite which I mentioned as a locality for the dogtooth spar,
considerable may be obtained in it and on its western edge near the
ceiling. A ladder about thirteen feet long is used for attending the
lights, and may generally be borrowed, and access to the remainder
of this pocket thus gained. Datholite is also very characteristic in
appearance, and can only be confounded with some forms of calcite
occurring near it. It occurs in small glassy, nearly globular crystals;
they are generally not over three-sixteenths of an inch in diameter, and
generally pure and perfectly transparent, having a hardness of a little
over 5, and specific gravity of 3; as it generally occurs as a druse
upon the trap, or an apopholite, calcite, etc., this is seldom
attainable, however, and we have a very distinctive characteristic in
another test: this is the blowpipe, under which it at first intumesces
and then fuses to a transparent globule, and the flame, after playing
upon it, is of a deep green color. Nitric acid must be used to boil it
up with, and with it it may be readily gelatinized. This last test will
seldom be necessary, however, and may be dispensed with if the hardness
and blowpipe reactions may be ascertained.
_Apopholite_.--This beautiful mineral has been found in fair abundance
at times in Shafts No. 1 and 2 in pockets, and seldom in place, most of
it being taken from the loose stone at the mouth of the shaft, and it
may generally be found on the dump. It is readily mistaken for calcite
by the miners and those unskilled in mineralogy, but a drop of acid will
quickly show the difference. The sizes of the crystals are very various,
from an eighth of an inch long or thick, to, in one case, an inch and
a half. The colors have been varied from white to nearly all tints,
including pink, purple, blue, and green; the white variety is, however,
the most abundant, and makes a handsome cabinet specimen. The crystals
are generally packed together in a mass, but are frequently set apart as
heavy druses of crystals having the form shown in Fig. 7. Sometimes,
as in the former grouping, the crystals are without the pyramidal
terminations, and are then right square prisms. The fracture being at
perfect right angles, distinguishes it from calcite. Its hardness is
generally fully 5, the specific gravity between 2.4 and 2.5; it is
difficult to fuse before the blowpipe, but is finally fused into an
opaque globule. Upon heating with nitric acid it partly dissolves, and
the remainder becomes flaky and gelatinous. Apopholite, although quite
rare, now may be bought from the men, or at least one of the engineers
of Shaft No. 2's elevator, and generally at low terms.
_Phrenite_.--This mineral is quite abundant in Shafts No. 1 and 2, in
very small masses, incrustations, and even in small crystals. It
occurs embedded in or incrusting the trap, and also with calcite and
apopholite. The only sure place to find it is at the southwest side of
an opening through the pile of drift rock under the trestle work of the
tramway, between shaft No. 1 and the dump, and within a few feet of a
number of wooden vats sunk into the ground seen just before descending
the hills and near the edge. Here on a number of blocks of trap it may
be found, a greenish white incrustation about as thick as a knife blade;
it also may be found on the main dump, and is sometimes found in plates
one-eighth of an inch thick, of a darker green color, upon calcite. Its
easiest distinguishment from the other minerals of this locality, with
which it might be confounded, is its great hardness of from 6 to 7.
It is very fragile and brittle, however, and is never perfectly
transparent, but quite opaque; its specific gravity is 2.9, and it is
readily fused before the blowpipe after intumescing. It partly dissolves
in acid without gelatinizing, leaving a flaky residue; it is a beautiful
mineral when in masses or crystals of a dark green color, but the best
place in the vicinity to secure specimens of this kind is, as I will
detail hereafter, at Paterson, N. J.
_Iron and Copper Pyrites_.--Both of these common but frequently
beautiful minerals occur in the tunnel and adjacent rocks in great
abundance. The crystals are generally about one-fourth of an inch in
diameter, and groups of these may be frequently obtained on the dump in
the shafts, especially No. 1 and 2, and where the rock is being cleared
away for the eastern entrance to the tunnel. They resemble each other
very much; the iron pyrites, however, is in cubical forms and having the
great hardness of from 6 to 7, while the copper pyrites, less abundant
and in forms having triangles for bases, but having sometimes other
forms and a hardness of but 3 to 4. Both are similar in aspect to a
piece of brass, and cannot be mistaken for any other mineral. The form
of the copper pyrites is shown in Fig. 8; the iron is, as before noted,
in cubes, more or less modified.
_Stilbite_.--Small quantities of this beautiful mineral have been found
in Shaft No. 2, in a small bed of but a few square feet in area, but
quite thick and appearing much like natrolite. This bed was about one
hundred feet east from Shaft No. 2, and in the center of the heading
when it was at that point. It has been encountered since in small
quantities, and it would do well to look out for it in the fresh
tunneled portion after the date appended to this paper. It generally
occurs in the form shown in Fig. 9, grouped very similarly to natrolite,
and being right upon the rock or a thin bed of itself. The crystals are
generally half an inch long, but often less. The modifications of the
above form, which are frequent in this species, strike one forcibly of
the resemblance they bear to a broad stone spear head on a diminutive
scale, with a blunted edge; their hardness is about 4, specific gravity
2.2, the color generally a pearly white or grayish. After a long
boiling with nitric acid it gelatinizes, but it foams up and fuses to a
transparent glass before the blowpipe. A little stilbite may often be
found on the dumps.
_Laumonite_ occurs in very small quantities on calcite or apopholite,
and can hardly be expected to be found on the trip; but as it might be
found, I will detail some of its characteristics. Hardness 4, specific
gravity 2.3; it generally occurs in small crystals, but more frequently
in a crumbly, chalky mass, which it becomes upon exposure to the air.
The crystals are generally transparent and frequently tinged yellow in
color. It gelatinizes by boiling with acid, and after intumescing before
the blowpipe, fuses to a frothy mass. To keep this mineral when in
crystals from crumbling upon exposure it may be dipped in a thin mastic
varnish or in a gum-arabic solution.
_Heulandite_.--This rare mineral has been found under the same
conditions as laumonite in Shaft No. 2, but it is seldom to be met with,
and then in small crystals. It is of a pure white color, sometimes
transparent. It intumesces and readily fuses before the blowpipe, and
dissolves in acid without gelatinizing. Hardness 4, specific gravity
2.2.
The few other minerals occurring in the tunnel are so extremly rare as
not to be met with by any other than an expert, and it is impossible
to detail the localities, as they generally occur as minute druses or
incrustations upon other minerals with which they may be confounded, and
have been removed as soon as discovered. The minerals referred to are
analcime, chabazite, Thompsonite, and finally, the mineral which I first
found in this formation, Hayesine, which is extremely rare, and of which
I only obtained sufficient to cover a square inch. The particulars in
regard to its locality, etc., maybe found in the _American Journal of
Sciences_ for June, page 458. I will now sum up the characteristics of
these several minerals of this locality in the table:
-------------------------------------------------------------------------------
| | | | | |
Name. | H. |Sp.|Action of |Action of |Color.|Appearance.
| |Gr.|Blowpipe. |hot acid. | |
----------+-----+---+-----------------+-----------------+------+---------------
| | | | | |
Calcite | 3 |2.6|Infusible, |Soluble with |White |Like Fig.
| | |but glows |effervescence | |3 and 4.
| | | | | |
Natrolite | 5 |2.2|Readily fused |Forms a jelly | do. |Like Fig 5.
| | |to clear globule | | |
| | | | | |
Pectolite | 4 |2.5| do. | do. do. | do. |Divergent
| | | | | |fibers, Fig. 6.
| | | | | |
Datholite | 5 |3.0|Intumesces, fused|Forms a jelly |Color-|Small, nearly
| | |to clear globule,| |less |spherical, etc.
| | |gives green flame| |white |
| | | | | |
Apopholite| 5 |2.5|Difficult, fused |Partly soluble |Tinted|Like Fig. 7.
| | |to opaque globule|in nitric acid | |
| | | | | |
Phrenite | 6 |2.9|Intomesces, fused|Partly soluble |Green-|In tables and
|to 7 | |to clear globule |in nitric acid, |ish |incrustations.
| | | |leaving flakes | |
| | | | | |
Iron | 6 |5.0|Burns and yields | |Brass |Cubical.
pyrites |to 7 | |a black globule, | | |
| | |decrepitates | | |
| | | | | |
Copper | 3 |4.2| do. do. | | do. |Tetrahedronal.
pyrites |to 4 | | | | |
| | | | | |
Stilbite | 4 |2.2|Intumesces and |Difficult; jelly |White |Like Fig. 8.
| | |fuses readily |on long boiling | |
| | | |with nitric acid.| |
| | | | | |
Laumonite | 4 |2.3|Intumesces and |Readily | do. |Generally
|to 0 | |fuses to frothy |gelatinizes | |chalky.
| | |mass | | |
| | | | | |
Heulandite| 4 |2.2|Intumesces and |Soluble, no | do. |In right
| | |readily fuses |jelly | |rhomboidal
| | | | | |prisms.
| | | | | |
-------------------------------------------------------------------------------
_To Distinguish the Minerals together the one from the other_.--Calcite
by effervescing on placing a drop of acid upon it. Natrolite resembles
stilbite, but may be distinguished by gelatinizing readily with
hydrochloric acid and by not intumescing when heated before the
blowpipe; from the other minerals by the form of the crystals and their
setting, also the locality in the tunnel in which it was found.
Pectolite sometimes resembles some of the others, but may be readily
distinguished by its _tough_ long fibers, not brittle like natrolite.
Datholite may generally be distinguished by the form of its crystals and
their glassy appearance, with great hardness, and by tingeing the flame
from the blowpipe of a true green color. Apopholite is distinguished
from calcite, as noticed under that species, and from the others by its
form, difficult fusibility, and part solubility.
Phrenite is characterized by its hardness, greenish color, occurrence,
and action of acid. Iron pyrites is always known by its brassy metallic
aspect and great hardness. Copper pyrites, by its aspect from the other
minerals, and from iron pyrites by its inferior hardness and less
gravity.
Stilbite is characterized by its form, difficult gelatinizing, and
intumescence before the blowpipe; from natrolite as mentioned under that
species.
Laumonite is known by its generally chalky appearance and a probable
failure in finding it.
Heulandite is distinguished from stilbite by its crystals and perfect
solubility; from apopholite by form of crystals.
In the next part of this paper I will commence with Staten Island.
July 1, 1882. (_To be continued_.)
* * * * *
ANTISEPTICS.
The author has endeavored to ascertain what agents are able to destroy
the spores of bacilli, how they behave toward the microphytes most
easily destroyed, such as the moulds, ferments, and micrococci, and if
they suffice at least to arrest the development of these organisms in
liquids favorable to their multiplication. His results with phenol,
thymol, and salicylic acid have been unfavorable. Sulphurous acid
and zinc chloride also failed to destroy all the germs of infection.
Chlorine, bromine, and mercuric chloride gave the best results;
solutions of mercuric chloride, nitrate, or sulphate diluted to 1 part
in 1,000 destroy spores in ten minutes.--_R. Koch_.
* * * * *
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