Scientific American Supplement, No. 392, July 7, 1883
by
Various
Part 1 out of 3
Produced by Olaf Voss, Don Kretz, Juliet Sutherland,
Charles Franks and the DP Team
[Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 392
NEW YORK, JULY 7, 1883
Scientific American Supplement. Vol. XVI, No. 392.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ELECTRICITY AND MAGNETISM.--Improved Dynamo Machine.
Eight figures.
An Improved Manganese Battery.--By GEO. LEUCHS.
The Cause of Evident Magnetism in Iron, Steel, and other Magnetic
Metals.--By Prof. D. E. HUGHES. Neutrality.--Superposed
Magnetism.--Elastic Nature of the Ether Surrounding the Magnetic
Molecules. 3 figures.
II. ENGINEERING.--The Westinghouse Brake. 2 figures.
Hydraulic Elevators and Motors.--By B. F. JONES.--Bearing
upon the Water Supply of Cities.--Cost of Water used.--Objectionable
effects on Water Works.--Best method of arranging water
supply.--Cause of Accidents.--Advantages of Water Motors over
Steam Engines.--Rates for Water Motors.
Water Supply of Small Towns.--Process of Softening Hard
Water. Six figures.
Improved Water Meter. Several figures.
III. TECHNOLOGY.--Washing Machine for Wool. 1 figure.
Increasing the Illuminating Power of Gases, etc.--By V. POPP.--
3 figures.
Preventing Iron from Rusting.
An Elastic Mass for Confectioners' Use.
Caoutchouc.
Photographic Action Studied Spectroscopically.
Salt and Lime.
Renewing Paint without Burning.
A Green or Golden Color for all Kinds of Brass.--By E. PULCHER.
Vinegar.
The Preservation of Meat by Carbonic Acid.
On the Adulteration of Soap.--By Dr. H. BRACKEBUSCH.
IV. CHEMISTRY.--Testing Olive Oil.--By Dr. O. BACH.
On the Theory of the Formation of Compound Ethers.
The Alizarine Industry.
Reduction of Oxidized Iron by Carbonic Oxide.
V. MEDICINE AND HYGIENE.--Bovine and Human Milk; the Difference
in its Action and Composition.--By C. HUSSON.
Cereal Foods in their Relation to Health and Disease.--By F. R.
CAMPBELL.
Moist Air in Living Rooms.
The Developmental Significance of the Human Physiognomy.--
By E. D. COPE.--Numerous illustrations.
VI. NATURAL HISTORY.--The Diamond Fields of South Africa.
Sponges at the Bahamas.
Testing Fish Ova for Impregnation.
VII. MISCELLANEOUS.--The Production of Fire. 4 figures.
St. Blaise.--The winner of the Derby. 1 illustration.
* * * * *
IMPROVED DYNAMO MACHINE.
The continuous current and the alternating current generators invented
by Dr. J. Hopkinson and Dr. Alexander Muirhead are peculiarly
interesting as being probably the first in which the bobbins of the
armature were wound with copper ribbon and arranged on a disk armature
much in the same way as was afterward done by Sir William Thomson and by
Mr. Ferranti. In the Muirhead-Hopkinson machine the armature coils are
attached to a soft iron ring, whereas in the Ferranti the iron core is
dispensed with, and a gain of lightness in the armature or rotating part
effected; this advantage is of considerable importance, though Messrs.
Hopkinson and Muirhead can of course reduce the weight of this iron core
to insignificant proportions.
[Illustration: HOPKINSON & MUIRHEAD'S DYNAMO-ELECTRIC GENERATOR.]
The general form of this generator is clearly shown by the side and end
elevation.
The armature is made by taking a pulley and encircling it with a rim of
sheet-iron bands, each insulated from the other by asbestos paper. On
one or both sides of the rim thus formed, radial slots are cut to admit
radial coils of insulated copper wire or ribbon, so that they lie in
planes parallel to the plane of the pulley. In the continuous current
machine coils are placed on both sides of the iron rim and arranged
alternately, that on the one side always covering the gap between two on
the other side. In this way, when a coil on one side of the rim is at
its "dead point" and yields its minimum of current, the corresponding
coil on the other side is giving out its maximum.
The field magnets are made in a similar manner to the armature and run
in circles parallel to the rim of the latter. The cores may be built up
of wrought iron as the rim of the armature is; but it is found cheaper
to make them of solid wrought or cast iron. To stop the local induced
currents in the core, however, Messrs. Muirhead and Hopkinson cut
grooves in the faces of the iron cores, and fill them up with sheet-iron
strips insulated from each other, similar to the sheet-iron rim of the
armature.
The coils, both in the armature and electro-magnets, are packed as
closely as they may to each other, and have thus a compressed or
quadrilateral shape. The arrangement is shown in Figs. 1 and 2, which
represent, in side view and plan, the armature pulley with the soft iron
rim and coils attached. There a is the pulley which is keyed to the
shaft of the machine, and is encircled with bands of sheet iron, b,
insulated from each other by ribbons of asbestos paper laid between
every two bands. When the rim has been built up in this way, radial
holes are drilled through it from the outer edge inward, and the whole
rim is bound together by bolts, d, inserted in the holes and secured by
cottars, e. Radial slots are then cut on each side of the rim all round,
and the coils of wire mounted on them.
Figs. 3 and 4 show the armature of the continuous current dynamo, with
the coils on one side of the rim, half way between the coils on the
other side, so as to give a more continuous current. In the alternating
current machine the slots on the opposite faces are face to face.
Figs. 5 and 9 illustrate the complete continuous current machine, Fig.
9 showing the internal arrangement of the field magnets, and Fig. 5 the
external frame of cast iron supporting them. In these figures a is the
armature already described, b b are the cores of the electro-magnets
with a strong cast iron backing, c c; d d are the exciting coils or
field magnets, so connected that the poles presented to the armature are
alternately north and south, thus bringing a south pole on one side of
the armature opposite a north pole on the other side.
The commutator, e, is arranged to prevent sparking when the brushes
leave a contact piece. This is done by splitting up the brushes into
several parts and inserting resistances between the part which leaves
the contact piece last and the rest of the circuit. This resistance
checks the current ere the final rupture of contact takes place.
Figs. 6 and 7 will explain the structure of the commutator. Here a a a
are the segments or contact pieces insulated from each other, and b' b
b are the collecting brushes carried on a spindle, c c'. One of these
brushes, b', is connected to the spindle, c, through an electrical
resistance of plumbago, arranged as shown in Fig. 7, where d e are metal
cylinders, d being in contact with the brush, b', while e is in contact
with the spindle, c. The space, f, between these two cylinders, d e, is
filled with a mixture of plumbago and lampblack of suitable resistance,
confined at the ends by ivory disks. The brush, b', is adjusted by
bending till it remains in contact with any segment of the commutator
for a short time after the other brushes have left contact with that
segment, and thus instead of sudden break of circuit and consequent
sparking, a resistance is introduced, and contact is not broken until
the current has been considerably reduced.
The contact segments are supported at both ends by solid insulating
disks; but they are insulated from each other by the air spaces between
them, where the brushes rub upon them.
The alternating current dynamo of Drs. Hopkinson and Muirhead differs
little in general construction from that we have described; except that
the commutator is very much simplified, and the armature bobbins are
placed opposite each other on both sides of the rim. Instead of forming
the coils into complete bobbins, Dr. Muirhead prefers to wind them in a
zigzag form round the grooved iron rim after the manner shown in Fig. 8,
which represents a plan and section of the alternating current armature.
This arrangement is simpler in construction than the bobbin winding, and
is less liable to generate self-induction current in the armature. Sir
William Thomson has adopted a similar plan in one of his dynamos. In
Fig. 8, a is the pulley fixed to the spindle of the machine, b b is
the iron rim, and c c are the zigzag coils of copper ribbon. The field
magnets are also wound in a similar manner.
It will be seen from our description that Drs. Hopkinson and Muirhead
have scarcely had sufficient credit given them for this interesting
machine, which so closely approximates to the Ferranti. One of their
alternating dynamos has been built, and was shown at the Aquarium
Exhibition. It works well, and is capable of supporting 300 Swan lights,
while in size and appearance it resembles the Ferranti machine in a
very striking manner. Drs. Muirhead and Hopkinson have also designed
a magneto-electric alternating current machine; but as it closely
resembles the machines described, with the exception that permanent
magnets are employed as field magnets, we need not dwell upon it
further.--_Engineering_.
* * * * *
AN IMPROVED MANGANESE BATTERY.
By GEORGE LEUCHS.
The Leclanche battery is distinguished for its simplicity, its small
internal resistance (0.7 to 1.0 Siemens unit), and that all chemical
action ceases when the current is broken, that it is not sensitive to
external influence, and by the self-renewal of the negative electrodes.
But on the opposite side the action is not very great (= 1.20 or 1.48
D.), and the zinc as well as the sal ammoniac are converted into
products that cannot be utilized.
I replace the solution of sal ammoniac by one of caustic potash or
soda (12 to 15 per cent.), and the thin zinc rods by zincs with larger
surfaces. In this manner, I obtain a powerful and odorless battery,
having all the valuable qualities of the Leclanche, and one that
permits of a renewal of the potash solution as well as of the negative
electrode.
The electromotive power of this element may be as high as 1.8 D. The
same pyrolusite (binoxide of manganese) cylinder used with the same thin
rod of zinc will precipitate 75 per cent. more copper from solution in
an hour when caustic potash is used than when sal ammoniac is employed.
But by replacing the thin zinc rod by a zinc cylinder of large surface,
21/2 times as much copper is precipitated in the same time.
The more powerful action of such a pair is explained by the stronger
excitation and more rapid regeneration that the negative electrodes
undergo from the oxidizing action of the air in the potash solution, as
well as by the fact that this solution is a better conductor than the
sal ammoniac solution. The potash solution does not crystallize easily,
hence the negative electrode remains free from crystals and does not
require filling up with water. Zinc dissolves only while in contact
with negative bodies, hence there is no unnecessary consumption of zinc
either in the open or closed circuit.
When the potash lye has become useless, I regenerate it by removing the
zinc in the following manner: I pour the solution from the cells, put
it in a suitable vessel, where I add water to replace that already
evaporated, and then shake it up well at the ordinary temperature with
hydrated oxide of zinc (zincic hydrate). Under this treatment the
greater portion of the zinc that had been chemically dissolved by the
potash is precipitated in the form of zinc hydrate, along with
some carbonate. The liquid is now allowed to settle, and the clear
supernatant solution is poured back again into the battery cells. The
battery has rather greater electromotive force when this regenerated lye
is used, because certain foreign matters from the carbon, like sulphur,
chlorine, sulphuric acid, etc., are removed by this treatment.
The regeneration of the (brown coal) carbon goes on of itself, beneath
the lye, through the oxidizing action of the atmospheric air; it is
advantageous to have a part of the carbon sticking out of the liquid. Of
course the regeneration takes place much more quickly if the electrodes
are taken out and exposed to the air. In this case the carbon electrode
need not be very thick, and can be flat or of tubular form. In the
former case it must have a large volume, and the massive cylindrical
form is recommended. The zinc electrode must be kept covered deeply with
potash. The cells must have free access of air, and the potash must be
replaced as soon as it is exhausted.--_Chem. Zeit_.
* * * * *
[Concluded from SUPPLEMENT No. 390, page 6217.]
THE CAUSE OF EVIDENT MAGNETISM IN IRON, STEEL, AND OTHER MAGNETIC
METALS.
[Footnote: Paper lately read before the Society of Telegraph Engineers
and Electricians.]
By Professor D. E. HUGHES, F.R.S., Vice-President.
NEUTRALITY.
The apparatus needed for researches upon evident external polarity
requires no very great skill or thought, but simply an apparatus to
measure correctly the force of the evident repulsion or attraction; in
the case of neutrality, however, the external polarity disappears, and
we consequently require special apparatus, together with the utmost care
and reflection in its use.
From numerous researches previously made by means of the induction
balance, the results of which I have already published, I felt convinced
that in investigating the cause of magnetism and neutrality I should
have in it the aid of the most powerful instrument of research ever
brought to bear upon the molecular construction of iron, as indeed of
all metals. It neglects all forces which do not produce a change in the
molecular structure, and enables us to penetrate at once to the interior
of a magnet or piece of iron, observing only its peculiar structure
and the change which takes place during magnetization or apparent
neutrality.
The induction balance is affected by three distinct arrangements of
molecular structure in iron and steel, by means of which we have
apparent external neutrality.
Fig 1 shows several polar directions of the molecules as indicated
by the arrows. Poisson assumed as a necessity of his theory, that
a molecule is spherical; but Dr. Joule's experimental proof of the
elongation of iron by one seven-hundred and-twenty-thousandth of its
length when magnetized, proves at least that its form is not spherical;
and, as I am unable at present to demonstrate my own views as to its
exact form, I have simply indicated its polar direction by arrows--the
dotted oval lines merely indicating its limits of free elastic rotation.
In Fig. 1, at A, we have neutrality by the mutual attraction of each
pair of molecules, being the shortest path in which they could satisfy
their mutual attractions. At B we have the case of superposed magnetism
of equal external value, rendering the wire or rod apparently neutral,
although a lower series of molecules are rotated in the opposite
direction to the upper series, giving to the rod opposite and equal
polarities. At C we have the molecules arranged in a circular chain
around the axis of a wire or rod through which an electric current
has passed. At D we have the evident polarity induced by the earth's
directive influence when a soft iron rod is held in the magnetic
meridian. At E we have a longitudinal neutrality produced in the same
rod when placed magnetic west, the polarity in the latter case being
transversal.
In all these cases we have a perfectly symmetrical arrangement, and I
have not yet found a single case in well-annealed soft iron in which I
could detect a heterogeneous arrangement, as supposed by Ampere, De la
Rive, Weber, Wiedermann, and Maxwell.
We can only study neutrality with perfectly soft Swedish iron. Hard
iron and steel retain previous magnetizations, and an apparent external
neutrality would in most cases be the superposition of one magnetism
upon another of equal external force in the opposite direction, as shown
at B, Fig. 1. Perfectly soft iron we can easily free, by vibrations,
from the slightest trace of previous magnetism, and study the neutrality
produced under varying conditions.
[Illustration: FIG. 1.]
If we take a flat bar of soft iron, of 30 or more centimeters in
length, and hold it vertically (giving while thus held a few torsions,
vibrations, or, better still, a few slight blows with a wooden mallet,
in order to allow its molecules to rotate with perfect freedom), we find
its lower end to be of strong north polarity, and its upper end south.
On reversing the rod and repeating the vibrations, we find that its
lower end has precisely a similar north polarity. Thus the iron is
homogeneous, and its polarity symmetrical. If we now magnetize this rod
to produce a strong south pole at its lower portion, we can gradually
reverse this polarity, by the influence of earth's magnetism, by
slightly tapping the upper extremity with a small wooden mallet. If
we observe this rod by means of a direction needle at all parts, and
successively during its gradual passage from one polarity to the other,
there will be no sudden break into a haphazard arrangement, but a
gradual and perfectly symmetrical rotation from one direction to that of
the opposite polarity.
If this rod is placed east and west, having first, say, a north polarity
to the right, we can gradually discharge or rotate the molecules to
zero, and as gradually reverse the polarity by simply inclining the rod
so as to be slightly influenced by earth's magnetism; and at no portion
of this passage from one polarity to neutrality, and to that of the
opposite name, will there be found a break of continuity of rotation or
haphazard arrangement. If we rotate this rod slowly, horizontally or
vertically, taking observations at each few degrees of rotation of an
entire revolution, we find still the same gradual symmetrical change
of polarity, and that its symmetry is as complete at neutrality as in
evident polarity.
In all these cases there is no complete neutrality, the longitudinal
polarity simply becoming transversal when the rod is east and west.
F, G, H, I, J, Fig. 1, show this gradual change, H being neutral
longitudinally, but polarized transversely. If, in place of the rod,
we take a small square soft iron plate and allow its molecules freedom
under the sole influence of the earth's magnetism, then we invariably
find the polarity in the direction of the magnetic dip, no matter in
what position it be held, and a sphere of soft iron could only be
polarized in a similar direction Thus we can never obtain complete
external neutrality while the molecules have freedom and do not form an
internal closed circle of mutual attractions; and whatever theory we may
adopt as to the cause of polarity in the molecule, such as Coulomb's,
Poisson's, Ampere's, or Weber's, there can exist no haphazard
arrangement in perfectly soft iron, as long as it is free from all
external causes except the influence of the earth; consequently these
theories are wrong in one of their most essential parts.
We can, however, produce a closed circle of mutual attraction in iron
and steel, producing complete neutrality as long as the structure is not
destroyed by some stronger external directing influence.
Oersted discovered that an external magnetic needle places itself
perpendicular to an electric current; and we should expect that, if the
molecules of an iron wire possessed inherent polarity and could rotate,
a similar effect would take place in the interior of the wire to that
observed by Oersted. Wiedermann first remarked this effect, and it has
been known as circular magnetism. This circle, however, consists really
in each molecule having placed itself perpendicular to the current,
simply obeying Oersted's law, and thus forming a complete circle in
which the mutual attractions of the molecules forming that circle are
satisfied, as shown as C, Fig. 1. This wire becomes completely neutral,
any previous symmetrical arrangement of polarity rotating to form its
complete circle of attractions; and we can thus form in hard iron and
steel a neutrality extremely difficult to break up or destroy. We have
evident proof that this neutrality consists of a closed chain, or
circle, as by torsion we can partially deflect them on either side; thus
from a perfect externally neutral wire, producing either polarity, by
simple mechanical angular displacement of the molecules, as by right or
left handed torsion.
If we magnetize a wire placed east and west, it will retain this
polarity until freed by vibrations, as already remarked. If we pass an
electric current through this magnetized wire, we can notice the gradual
rotation of the molecules, and the formation of the circular neutrality.
If we commence with a weak current, gradually increasing its strength,
we can rotate them as slowly as may be desired. There is no sudden break
or haphazard moment of neutrality: the movements to perfect zero are
accomplished with perfect symmetry throughout.
We can produce a more perfect and shorter circle of attractions by the
superposition of magnetism, as at B, Fig. 1. If we magnetize a piece
of steel or iron in a given direction with a strong magnetic directing
power, the magnetism penetrates to a certain depth. If we slightly
diminish the magnetizing power, and magnetize the rod in a contrary
direction, we may reduce it to zero, by the superposition of an exterior
magnetism upon one of a contrary name existing at a greater depth; and
if we continue this operation, gradually diminishing the force at each
reversal, we can easily superpose ten or more distinct symmetrical
arrangements, and, as their mutual attractions are satisfied in a
shorter circle than in that produced by electricity, it is extremely
difficult to destroy this formation when once produced.
The induction balance affords also some reasons for believing that the
molecules not only form a closed circle of attractions, as at B, but
that they can mutually react upon each other, so as to close a circle
of attractions as a double molecule, as shown at A. The experimental
evidence, however, is not sufficient to dwell on this point, as the
neutrality obtained by superposition is somewhat similar in its external
effects.
We can produce a perfectly symmetrical closed circle of attractions of
the nature of the neutrality of C, Fig. 3, by forming a steel wire into
a closed circle, 10 centimeters in diameter, if this wire is well joined
at its extremities by twisting and soldering. We can then magnetize this
ring by slowly revolving it at the extremity of one pole of a strong
permanent magnet; and, to avoid consequent poles at the part last
touching the magnet, we should have a graduating wedge of wood, so that
while revolving it may be gradually removed to greater distance. This
wire will then contain no consequent points or external magnetism: it
will be found perfectly neutral in all parts of its closed circle. Its
neutrality is similar to C, Fig. 3; for if we cut this wire at any point
we find extremely strong magnetic polarity, being magnetized by this
method to saturation, and having retained (which it will indefinitely)
its circle of attractions complete.
I have already shown that soft iron, when its molecules are allowed
perfect freedom by vibration, invariably takes the polarity of the
external directing influence, such as that of the earth, and it does so
even with greater freedom under the influence of heat. Manufacturers of
electro-magnets for telegraphic instruments are very careful to choose
the softest iron and thoroughly anneal it; but very few recognize the
importance as regards the position of the iron while annealing it under
the earth's directing influence. The fact, however, has long since been
observed.
Dr. Hooke, 1684, remarked that steel or iron was magnetized when heated
to redness and placed in the magnetic meridian. I have slightly varied
this experiment by heating to redness three similar steel bars, two
of which had been previously magnetized to saturation, and placed
separately with contrary polarity as regards each other, the third being
neutral. Upon cooling, these three bars were found to have identical and
similar polarity. Thus the molecules of this most rigid material, cast
steel, had become free at red heat, and rotated under the earth's
magnetic influence, giving exactly the same force on each; consequently
the previous magnetization of two of these bars had neither augmented
nor weakened the inherent polarity of their molecules. Soft iron gave
under these conditions by far the greatest force, its inherent polarity
being greater than that of steel.
I have made numerous other experiments bearing upon the question of
neutrality, but they all confirm those I have cited, which I consider
afford ample evidence of the symmetrical arrangement of neutrality.
SUPERPOSED MAGNETISM.
Knowing that by torsion we can rotate or diminish magnetism, I was
anxious to obtain by its means a complete rotation from north polarity
to neutrality, and from neutrality to south polarity, or to completely
reverse magnetic polarity by a slight right or left torsion.
I have succeeded in doing this, and in obtaining strong reversal of
polarities, by superposing one polarity given while the rod is under a
right elastic torsion, with another of the opposite polarity given under
a left elastic torsion, the neutral point then being reached when the
rod is free from torsion. The rod should be very strongly magnetized
under its first or right-hand torsion, so that its interior molecules
are rotated, or, in other words, magnetized to saturation; the second
magnetization in the contrary sense and torsion should be feebler, so
as only to magnetize the surface, or not more than one-half its depth;
these can be easily adjusted to each other so as to form a complete
polar balance of force, producing, when the rod is free from torsion,
the neutrality as shown at B, Fig. 1.
The apparatus needed is simply a good compound horseshoe permanent
magnet, 15 centimeters long, having six or more plates, giving it a
total thickness of at least 3 centimeters. We need a sufficiently
powerful magnet, as I find that I obtain a more equal distribution of
magnetism upon a rod or strip of iron by drawing it lengthwise over a
single pole in a direction from that pole, as shown in Fig. 2; we can
then obtain saturation by repeated drawings, keeping the same molecular
symmetry in each experiment.
In order to apply a slight elastic torsion when magnetizing rods or
wires, I have found it convenient to attach two brass clamp keys to the
extremities of the rods, or simply turn the ends at right angles, as
shown in the following diagram, by which means we can apply an elastic
twist or torsion while drawing the rod over the pole of the permanent
magnet. We can thus superpose several and opposite symmetrical
structures, producing a polar north or south as desired, greatly in
excess of that possible under a single or even double magnetization, and
by carefully adjusting the proportion of opposing magnetisms, so that
both polarities have the same external force, the rod will be at perfect
external neutrality when free from torsion.
[Illustration: FIG. 2.]
If we now hold one end of this rod at a few centimeters distance from
a magnetic directive needle, we find it perfectly neutral when free
of torsion, but the slightest torsion right or left at once produces
violent repulsion or attraction, according to the direction of the
torsion given to the rod, the iron rod or strips of hoop-iron which
I use for this experiment being able, when at the distance of five
centimeters from the needle, to turn it instantly 90 deg. on either side of
its zero.
The external neutrality that we can now produce at will is absolute, as
it crosses the line of two contrary polarities, being similar to the
zero of my electric sonometer, whose zero is obtained by the crossing of
two opposing electric forces.
This rod of iron retains its peculiar powers of reversal in a remarkable
degree, a condition quite different to that of ordinary magnetization,
for the same rod, when magnetized to saturation under a single ordinary
magnetism, loses its evident magnetism by a few elastic torsions, as I
have already shown; but when it is magnetized under the double torsion
with its superposed magnetism, it is but slightly reduced by variations
or numerous torsions, and I have found it impossible to render this
rod again free from its double polar effects, except by strongly
remagnetizing it to saturation with a single polarity. The superposed
magnetism then becomes a single directive force, and we can then by a
few vibrations or torsions reduce the rod to its ordinary condition.
The effects of superposed magnetism and its double polarity I have
produced in a variety of ways, such as by the electro-magnetic influence
of coils, or in very soft iron simply by the directive influence of
the earth's magnetism, reversing the rod and torsions when held in
the magnetic meridian, these rods when placed magnetic west showing
distinctly the double polar effects.
It is remarkable, also, that we are enabled to superpose and obtain
the maximum effects on thin strips of iron from 1/4 to 1/2 millimeter in
thickness, while in thicker rods we have far less effect, being masked
by the comparatively neutral state of the interior, the exterior
molecules then reaching upon those of the interior, allowing them to
complete in the interior their circle of attractions.
I was anxious to obtain wires which would preserve this structure
against the destructive influence of torsion and vibrations, so that I
could constantly employ the same wires without the comparatively long
and tedious process of preparation. Soft iron soon loses the structure,
or becomes enfeebled, under the constant to and fro torsions requisite
where we desire a constant change of polarity, as described later in the
magnetic bells. Hard steel preserves its structure, but its molecular
rigidity is so great that we obtain but mere traces of any change of
polarity by torsion. I have found, however, that fine cast drill steel,
untempered, of the kind employed by watchmakers, is most suitable;
these are generally sold in straight lengths of 30 centimeters. Wires
1 millimeter in diameter should be used, and when it is desired to
increase the force, several of these wires, say, nine or ten, should be
formed into a single rod or bunch.
The wire as sold is too rigid to give its maximum of molecular rotation
effect. We must therefore give it two entire turns or twists to the
right, and strongly magnetize it on the north pole of the magnet while
under torsion. We must again repeat this operation in the contrary
direction, after restoring the wire to its previous position, giving now
two entire turns to the left and magnetizing it on the south pole. On
restoring the wire to its original place, it will be extremely flexible,
and we may now superpose several contrary polarities under contrary
torsions, as already described.
The power of these wires, if properly prepared, is most remarkable,
being able to reverse their polarity under torsion, as if they were
completely saturated; and they preserve this power indefinitely if not
touched by a magnet. It would be extremely difficult to explain the
action of the rotative effects obtained in these wires under any other
theory than that which I have advanced; and the absolute external
neutrality that we obtain in them when the polarities are changing, we
know, from their structure, to be perfectly symmetrical.
I was anxious to show, upon the reading of this paper, some mechanical
movement produced by molecular rotation, consequently I have arranged
two bells that are struck alternately by a polarized armature put in
motion by the double polarized rod I have already described, but whose
position, at three centimeters distant from the axis of the armature,
remains invariably the same. The magnetic armature consists of a
horizontal light steel bar suspended by its central axle; the bells are
thin wine glasses, giving a clear musical tone loud enough, by the force
with which they are struck, to be clearly heard at some distance. The
armature does not strike these alternately by a pendulous movement, as
we may easily strike only one continuously, the friction and inertia of
the armature causing its movements to be perfectly dead beat when not
driven by some external force, and it is kept in its zero position by a
strong directive magnet placed beneath its axle.
The mechanical power obtained is extremely evident, and is sufficient to
put the sluggish armature in rapid motion, striking the bells six times
per second, and with a power sufficient to produce tones loud enough to
be clearly heard in all parts of the hall of the Society. As this is
the first direct transformation of molecular motion into mechanical
movement, I am happy to show it on this occasion.
There is nothing remarkable in the bells themselves, as they evidently
could be rung if the armature was surrounded by a coil, and worked by an
electric current from a few cells. The marvel, however, is in the small
steel superposed magnetic wire producing by slight elastic torsions from
a single wire, one millimeter in diameter, sufficient force from mere
molecular rotation to entirely replace the coil and electric current.
ELASTIC NATURE OF THE ETHER SURROUNDING THE MAGNETIC MOLECULES.
During these researches I have remarked a peculiar property of
magnetism, viz., that not only can the molecules be rotated through any
degree of arc to its maximum, or saturation, but that, while it requires
a comparatively strong force to overcome its rigidity or resistance to
rotation, it has a small field of its own through which it can move with
excessive freedom, trembling, vibrating, or rotating through a small
degree with infinitely less force than would be required to rotate it
permanently on either side. This property is so marked and general that
we can observe it without any special iron or apparatus.
Let us take a flat rod of ordinary hoop iron, 30 or more centimeters
in length. If, while holding this vertically, we give freedom to its
molecules by torsions, vibrations, or, better still, by a few blows with
a wooden mallet upon its upper extremity, we find, as is well known,
that its lower portion is strongly north, and its upper south. If we
reverse this rod, we now find it neutral at both extremities. We might
here suppose that the earth's directing force had rotated the molecules
to zero, or transversely, which in reality it has done, but only to the
limit of their comparatively free motion; for if we reverse the rod to
its original position, its previous strong polarity reappears at both
extremities, thus the central point of its free motion is inclined to
the rod, giving by its free motion great symmetrical inclination and
polarity in one direction, but when reversed the inclination is reduced
to zero.
In Fig. 3, D shows the bar of iron when strongly polarized by earth's
magnetic influence, under vibrations, with a sufficient force to have
rotated its elastic center of action. C shows the same bar with its
molecules at zero, or transversal, the directing force of earth being
insufficient without the aid of mechanical vibration to allow them to
change. The dotted lines of D suppose the molecule to be in the center
of its free motion, while at C the molecules have rotated to zero, as
they are prevented from further rotation by being at the extreme end of
its free motion.
If, now, we hold the rod vertically, as at C, giving neutrality, and
give a few slight blows with a wooden mallet to its upper extremity, we
can give just the amount of freedom required for it to produce evident
polarity, and we then have equal polarity, no matter which end of the
bar is below, the center of its free rotation here being perfect, and
the rod perfectly neutral longitudinally when held east and west. If, on
the other hand, we have given too much freedom by repeated blows of the
mallet, its center of free motion becomes inclined with the molecules,
and we arrive at its first condition, except that it is now neutral at
D and polarized at C. From this it will be seen that we can adjust
this center of action, by vibrations or blows, to any point within the
external directing influence.
[Illustration: FIG. 3.]
We can perceive this effect of free rotation in a limited space in all
classes of iron and steel, being far greater in soft Swedish iron than
in hard iron or steel. A similar phenomenon takes place if we magnetize
a rod held vertically in the direction of earth's magnetism. It
then gives greater polarity than if magnetized east or west, and if
magnetized in a contrary sense to earth's magnetism, it is very feebly
magnetized, or, if the rod is perfectly soft, it becomes neutral after
strong magnetization. This property of comparative freedom, and the
rotation of its center of action, can be demonstrated in a variety of
ways. One remarkable example of it consists in the telephone. All those
who are thoroughly acquainted with electro-magnetism, and know that
it requires measurable time to charge an electro-magnet to saturation
(about one-fifteenth of a second for those employed in telegraphy),
were surprised that the telephone could follow the slightest change of
timbre, requiring almost innumerable changes of force per second. I
believe the free rotation I have spoken of through a limited range
explains its remarkable sensitiveness and rapidity of action, and,
according to this view, it would also explain why loud sounding
telephones can never repeat all the delicacy of timbre that is easily
done with those only requiring a force comprised in the critical limits
of its free rotation. This property, I have found, has a distinct
critical value for each class of iron, and I propose soon to publish
researches upon the molecular construction of steel and iron, in which
I have made use of this very property as a guide to the quality of the
iron itself.
The elastic rotation (in a limited space) of a molecule differs entirely
from that known as mechanical elasticity. In perfectly soft iron we have
feeble _mechanical_ elasticity, while in tempered steel we have
that elasticity at its maximum. The contrary takes place as regards
_molecular_ elasticity. In tempered steel the molecules are extremely
rigid, and in soft iron its molecular elasticity is at its maximum. Its
free motion differs entirely from that given it by torsion or stress. We
may assume that a molecule is surrounded by continuous ether, more of
the nature of a jelly than of that of a gas; in such a medium a molecule
might freely vibrate through small arcs, but a rotation extending beyond
its critical limit would involve a much greater expenditure of force.
The discovery of this comparatively free rotation of molecules, by means
of which, as I have shown, we can (without in any degree disturbing the
external mechanical elasticity of the mass) change the axes of their
free motion in any direction desired, has led me into a series of
researches which have only indirectly any relation with the theory of
magnetism. I was extremely desirous, however, of finding an experimental
evidence which in itself should demonstrate all portions of the theory,
and the following experiment, I believe, answers this purpose.
Let us take a square soft iron rod, five millimeters in diameter by
thirty or more centimeters in length, and force the molecules, by aid
of blows from a wooden mallet, as previously described, to have their
centers of free motion in one direction; the rod will (as already shown)
have polarity at both ends, when held vertically; but if reversed, both
ends become completely neutral.
If now we turn the rod to its first position, in which it shows strong
polarity, and magnetize it while held vertically, by drawing the north
pole of a sufficiently powerful permanent magnet from its upper to its
lower extremity, we find that this rod, instead of having south polarity
at its lower portion, as we should expect from the direction of the
magnetization, is completely neutral at both extremities, but if we
reverse the rod its fullest free powers of magnetization now appear in
the position where it was previously neutral. Thus, by magnetization, we
have completely rotated its free path of action, and find that we can
rotate this path as desired in any direction by the application of a
sufficient directing power.
If we take a rod as described, with its polarities evident when held
vertically, and its neutrality also evident when its ends are reversed
in the same magnetic field, we find that its polarity is equal at both
ends, and that it is in every way symmetrical with a perfect magnet. If
we _gradually_ reverse the ends and take observations of its condition
through each degree of arc passed over, we find an equal symmetrical
diminution of evident external polarity, until we arrive at neutrality,
when it has no external trace of inherent polarity; but its inherent
polarity at once becomes evident by a simple return to its former
position. Thus the rod has passed through all the changes from polarity
to neutrality, and from neutrality to polarity, and these changes have
taken place with complete symmetry.
The limits of this paper do not allow me to speak of the numerous
theoretical evidences as shown by the use of my induction balance. I
believe, however, that I have cited already experimental evidences to
show that what has been attributed to coercive force is really due to
molecular freedom or rigidity; that in inherent molecular polarity we
have a fact admitted by Coulomb, Poisson, Ampere, De la Rive, Weber,
Du Moncel, Wiedermann, and Maxwell; and that we have also experimental
evidence of molecular rotation and of the symmetrical character of
polarity and neutrality.
The experiments which I have brought forward in this paper, in addition
to those mentioned in my paper read before the Royal Society, will,
I hope, justify me in having advanced a theory of magnetism which I
believe in every portion allows at least experimental evidences of its
probable truth.
* * * * *
THE WESTINGHOUSE BRAKE.
Below we illustrate the main parts of the Westinghouse brake as applied
to a vehicle. The supplementary reservoir brake cylinder and triple
valve are shown in position, and as fitted upon the engine, tender, and
each vehicle of the train. Air compressed by a pump on the locomotive
to, say, 70 lb. or 80 lb. to the square inch fills the main reservoir on
the engine, and flowing through the driver's brake valve and main pipe,
also charges the supplementary reservoirs throughout the train. When
a train is running, uniform air pressure exists throughout its
length--that is to say, the main reservoir on the engine, the pipe from
end to end of train, the triple valves and supplementary reservoirs on
each vehicle, are all charged ready for work, the brake cylinders being
empty and the brakes off. The essential principle of the system is,
that maintaining the pressure keeps the brakes off, but letting the air
escape from the brake pipe, purposely or accidentally, instantly applies
them. It follows, therefore, that the brake may be applied by the driver
or any of the guards, or if necessary by a passenger, by the separation
of a coupling, or the failure or injury to a vital part of the
apparatus, whether due to an accident to the train or to the brake; and
as the brake on each vehicle is complete in itself and independent,
should the apparatus on any one carriage be torn off, the brake will
nevertheless remain applied for almost any length of time upon the rest
of the train.
The triple valve, as will be seen, is simply a small piston, carrying
with it a slide valve, which can be moved up or down by increasing or
decreasing the pressure in the brake pipe. As soon as the air from the
main reservoir is turned into the brake pipe, by means of the driver's
valve, the piston is pushed up into the position shown, and air is
allowed to feed past it through a small groove into the reservoir. At
the same time the slide valve covers the port to the brake cylinder, and
is in such a position that the air from the latter may exhaust into the
atmosphere. The piston has now the same air pressure on both sides; but
if the pressure in the brake pipe is decreased, the piston and slide
valve are forced down, thereby uncovering the passage through which air
from the reservoir flows into the brake cylinder between the pistons,
thus applying the brakes. The brake pipe is shut off as soon as the
triple valve piston passes the groove. To release the brakes, the piston
and slide valves are again moved into the position shown, by the driver
turning air from the main reservoir into the brake pipe. The air in the
brake cylinder escapes, and at the same time the reservoir is recharged.
[Illustration: THE WESTINGHOUSE BRAKE.]
Fig. 2 represents two Westinghouse couplings connected. They are exactly
alike in all respects, and an air tight joint is made between them by
means of the rubber washers. These couplings are so constructed that the
air pressure within serves to tighten the joint, and they may be pushed
apart by the separation of the train without any injury. Such an
occurrence as already explained leads to the instant application of all
the brakes on the train.
By closing the small tap shown between the brake pipe and the triple
valve, the brake on any vehicle, if out of order, can be cut out of the
system. A release valve is also placed upon each cylinder as shown, so
that in the event of the brakes being applied by the separation of
the train, or the breaking of a pipe, or when the locomotive is not
attached, they can be released by allowing the air to escape from each
brake cylinder direct. The Westinghouse brake has been made to comply
thoroughly with the Board of Trade conditions. Many people, however, do
not appear to understand all that is involved in the second requirement,
which runs as follows: In case of accident, to be instantaneously
self-acting. This clearly implies: First, that accident to the train,
or to any of its vehicles, shall cause the instant application of
the brakes to the wheels of every vehicle in the train without the
intervention of the driver or guards. Secondly, that any injury, however
caused, which may impair the efficiency of the brake apparatus, shall,
in like manner, lead to the instant application of all the brakes on
the train. It then becomes impossible for a driver to run his train in
ignorance of any defect in his brake apparatus because such defect at
once discloses itself by applying the brakes and stopping the train.
Thirdly, that each vehicle shall carry its own brake power in such a
manner that the destruction of the brake apparatus on one or more of the
carriages shall not affect the efficiency of the brakes upon any of the
others. No continuous brake which does not comply with such conditions
can ever be satisfactory.--_The Engineer_.
* * * * *
HYDRAULIC ELEVATORS AND MOTORS.
[Footnote: Read at Buffalo meeting of the American Water-Works
Association May 15,1883.]
By B. F. JONES, Kansas City.
What I have to say in relation to elevators and motors will be mostly in
regard to questions that their uses necessarily bring up for settlement
at the water-works office; also to show how I have been able in a
measure to overcome some of the many difficulties that have presented
themselves, as well as to discuss and seek information as to the best
way of meeting others that still have to be dealt with. At the outset,
therefore, let me state that I am not an hydraulic engineer, nor have
I sufficient mechanical knowledge to undertake the discussion of the
construction or relative merits of either elevators or motors. This I
would respectfully suggest as a very proper and interesting topic for a
paper at some future meeting by some one of the many, eminent engineers
of this association.
The water-works of Kansas City is comparatively young, and my experience
only dates back six or seven years, or shortly after its completion.
At this time it was deemed advisable on account of the probable large
revenue to be derived from their use, to encourage the putting in of
hydraulic elevators by low water rates. With this end in view a number
of contracts were made for their supply at low special rates for a
period of years, and our minimum meter rate was charged in all other
cases, regardless of the quantity of water consumed. In most instances
these special rates have since been found much too low, parties paying
in this way being exceedingly extravagant in the use of elevators.
However, the object sought was obtained, and now they are very
extensively used. In fact, so much has their use increased, that the
question is no longer how to encourage their more general adoption, but
how to properly govern those that must be supplied. A present our works
furnish power to about 15 passenger and 80 freight elevators, and the
number is rapidly increasing.
Before going into details it seems proper to give at least a brief
description of our water-works, as my observations are to a great extent
local.
On account of the peculiar topography of Kansas City (and I believe it
has more topography to the square foot than any city in the country)
two systems of water supply have been provided, the high ground being
supplied by direct pumping, and a pressure of about 90 pounds maintained
in the business portion, and the lower part of the city being supplied
by gravity, from a reservoir at an elevation of 210 feet, thus giving
the business portions of the city, on high and low ground, about the
same pressure. By an arrangement of valves, a combination of these
two systems is effected, so that the Holly machinery can furnish an
increased fire pressure at a moment's notice, into either or both pipe
systems. Thus at some points the pressure is extremely high during the
progress of fires, causing difficulties that do not exist where the
gravity system of works is used exclusively.
Elevators have become an established institution, and in cities of any
commercial importance are regarded as a necessity, hotels, jobbing
houses, factories, and office buildings being considered as far behind
the times when not thus provided, as a city without a water supply or a
community without a "boom." The use of elevators has made it practicable
and profitable to erect buildings twice as high as were formerly thought
of. Perhaps some of the most notable examples of this are in New York
city, where such structures as the Mills building, the buildings of the
_Tribune, Evening Post_, and Western Union Telegraph Co.. tower high
above the surrounding blocks, monuments of architecture, that without
this modern invention would reflect little credit upon their designers.
It is now found less labor to go to to the fifth, sixth, or even tenth
floors of these great buildings than it was to reach the second or
third, before their use. In these days, merchants can shoot a ton of
goods to the top of their stores in less time than it would take to get
breath for the old hoist or "Yo, heave O" arrangement. Thousands of
dollars are sometimes expended on a single elevator, the cars are
miniature parlors, and the mechanism has perhaps advanced to nearly the
perfection of the modern steam engine. If then they have become such a
firmly established institution, their bearing upon the water supply of
cities is a subject to be carefully considered.
As before intimated, there are many questions involved in the use of
hydraulic elevators, that particularly concern towns supplied by direct
pumping, and perhaps other places where the supply by gravity is
somewhat limited. In a few larger cities supplied by ample reservoirs
and mains, some of the difficulties suggested are not serious. Very
little power is necessary to perform the actual work of lifting, with
either steam or hydraulic elevators, but on account of the peculiar
application of the power, and the great amount of friction to be
overcome, a very considerable power has to be provided. It has been
estimated, by good authorities, that not more than one-quarter of the
power expended in most cases is really utilized.
With all hydraulic elevators of which I have cognizance, as much water
is required to raise the empty cars as though they were loaded to
maximum capacity. Still, to be available for passenger purposes
elevators must have capacity of upward of 2,500 pounds, particularly in
hotels, where the cars are often arranged with separate compartments
underneath for baggage. In general use it is exceptional that passenger
elevators are fully loaded; on the contrary less than half a load is
ordinarily carried, and for this reason it would appear that no actual
benefit is derived from at least one-half of the water consumed. In this
connection it has occurred to me that passenger elevators could be built
at no great additional cost, with two cylinders, small and large, the
two piston rods of which could be connected so as to both operate the
same cable, either or both furnishing power, the smaller cylinder to be
used for light loads, the larger for heavy work, and the two together
for full capacity, this independent valve arrangement to be controlled
by a separate cable running through the car. Whether this plan is
practicable or not must be left to elevator manufacturers, but it seems
to me that with the Hale-Otis elevator for instance (which is conceded
to be one of the best) it could easily be accomplished. Certainly some
such arrangement would effect a great saving of water, and perhaps bring
water bills to a point that this class of consumers could afford to pay.
Hydraulic elevators where the water is used over and over again, by
being pumped from the discharge to elevated tanks, cut little or no
figure in connection with a city's water supply. When fuel, first cost,
attendance of an engineer, and the poor economy of the class of pumps
usually employed to perform this work are considered, the cost of
operating such elevators is greatly in excess of what it would be if
power were supplied direct from water mains, at any reasonable rate. The
following remarks will then relate almost exclusively to that class of
hydraulic elevators supplied with power directly from the water mains.
Let us now consider whether they are a desirable source of revenue, and
in this my knowledge does not exceed my actual experience. Few elevator
users appreciate the great quantity of water their elevators consume.
Even in Kansas City, where, on account of the high pressure carried,
much smaller cylinders than ordinarily are required, it is found that
passenger elevators frequently consume 500,000 to 800,000 gallons of
water per month, which will make a very considerable bill, at the most
liberal rates. I have, therefore, concluded that the quantity of water
was so large that, unless liberal concessions were made, it would be a
hardship to consumers to pay their water bills, and have therefore made
a special schedule, according to quantity, for elevators and motors,
these rates standing below our regular meter rates, and running to the
lowest point at which we think we can afford to furnish the water. This
schedule brings the rate below what we would receive for almost any
other legitimate use of water; and, in view of our rapidly increasing
consumption, and the probability of soon having to increase all our
facilities, it is an open question whether this will continue a
desirable source of revenue.
In Kansas City we have elevators of various manufacture: the Hale-Otis,
Ready, Smith & Beggs, O'Keefe, Kennedy, and perhaps others, each having
its peculiarities, but alike demanding large openings in the mains
for supply. These large openings are objectionable features with any
waterworks, and especially so with direct pumping. An occurrence from
this cause, about two years ago, is an experience I should not like
repeated, but is one that might occur whenever the pressure in the mains
is depended upon to throw fire streams. In this instance a large block
of buildings occupied by jobbing houses and having three elevators was
burned down, and the elevator connections broken early in the fire,
allowing the water to pour into the cellars in the volume of about
twelve ordinary fire streams. This immense quantity of water had to be
supplied from a 6-inch main, fed from only one end, which left little
pressure available for fighting the fire, and as a matter of course
failure to subdue the fire promptly was attributed to the water-works.
We have since had up hill work to restore confidence as to our ability
to throw fire streams, although we have demonstrated the fact hundreds
of times since.
From this time we have been gradually cutting down on the size of
openings for elevator supply, but under protest of the elevator agents,
who have always claimed that they should be allowed at least a 4-inch
opening in the mains, until we have found that under 80 to 90 pounds
pressure two to four 1-inch taps will answer the purpose, provided the
water pipes are of ample size.
The "water hammer" produced by the quick acting valves of elevators has
always been objectionable, both in its effect at the pumping-house
and upon water mains and connections. To obviate this, Engineer G. W.
Pearson has suggested the use of very large air chambers on the elevator
supply, and still smaller openings in the mains, his theory being that
the air chambers would not only materially decrease the concussion or
"water hammer," but that they would also act as accumulators of power
(or water under pressure) to be drawn from at each trip of the elevator,
and replaced when it was at rest. This plan I have never seen put to
actual test, but believe it to be entirely practicable, and that we will
have to ultimately adopt it.
All things considered, the plan of operating elevators from tanks in
the top of buildings, supplied by a small pipe connected with the
water-mains and arranged with a float valve to keep the tank filled, I
believe to be the best manner of supply, except for the great additional
cost of putting up such apparatus. By this arrangement the amount of
water consumed is no less, in fact it would ordinarily be more than with
a direct connection with the mains, but it has the advantage of taking
the water in the least objectionable manner. Still, if this mode of
supply were generally enforced, the large first cost, an additional
expense of operating, would undoubtedly deter many from using elevators.
Another evil in connection with the use of elevators, and which no doubt
is common, is the habit many parties have of keeping a key or wrench to
turn on and off the water at the curb. This we have sought to remedy
by embracing in our plumbers' rules the following: "All elevator
connections in addition to the curb stop for the use of the Water
Company must be provided with another valve where the pipe first enters
the building for the use of occupants of the building." Without this
extra valve it was found almost impossible to keep parties from using
the curb valve. In most cases the persons were perfectly responsible,
and as there was no intent to defraud the company by the act, they would
claim this privilege as a precaution against the pipes bursting or
freezing. This practice was very generally carried on, and was the
direct cause in at least two cases of very serious damage. In the
instances referred to, the pipes burst between the elevator and the
area wall of buildings, and the valves outside had become so worn
from frequent use that they would not operate, allowing the water to
literally deluge the basements before the water main could be turned
off.
One of the greatest causes of waste from elevators is the wearing out of
the piston packing, this being particularly troublesome in most of the
Western cities, where the water supplied is to a large extent from
turbid streams, carrying more or less fine sand or "grit," which cuts
out the packing of the pistons very rapidly. The only practicable remedy
for this is close inspection, to see that the pistons do not allow water
to pass, a fact that can readily be determined from the noise made in
the cylinder when the elevator is in motion going upward.
I have reserved one of the most annoying features of elevator supply for
the last, hoping to work myself into a mood to do the subject justice,
but doubt if it can be done in language proper to use before this
dignified body. I remember on one occasion the mayor of our city, in
discussing a job of plumbing, said that it seemed to him "that even a
plumber ought to know something about plumbing." Now it would seem that
even elevator agents ought to know something about elevators, but from
the following incident, which is but one of many, I am led to believe
that they are not infallible to say the least. Only a short time since,
one of these very reliable (?) agents reported at our office that he had
just attached a new indicator to the elevator of a leading hotel. He was
asked: "What does it register?" and promptly replied, "Cubic feet."
In this case our inspector had already made an examination, and had
correctly reported as follows: "Hale elevator; indicator started at zero
February 28; internal diameter of cylinder, 12 inches; travel of piston
for complete trip 301/4 feet; indicator registers for complete trip, 4."
When it is understood that we had for a long time been assuming that
elevator agents knew about all there was to know on the subject, a
comparison of statements of this agent and our inspector is somewhat
startling. Now let us see what the difference amounted to: At the end of
the month the indicator had registered 12,994; calling it cubic feet,
this register would equal 97,195 gallons. According to our inspector,
this same register would equal 578,233 gallons, or a difference of
nearly half a million of gallons for a single month. Our experience with
the agents in Kansas City has shown that they will, if allowed, put any
kind of an indicator on the most convenient point of any sort of an
elevator, without the slightest regard as to what it was intended to
indicate; then report it as registering cubic or lineal feet, whichever
they find the indicator marked. On the same principle they could as
well change the fulcrum of a Fairbanks scale, and then claim it weighed
pounds correctly, because pounds were marked upon the bar. We have
lately prepared a blank, upon which these agents are required to make a
detailed report upon the completion of an elevator before the water
will be turned on, which it is hoped will to some extent correct this
trouble.
I have come to regard an elevator indicator with a feeling of wonder.
Some years ago, when the "planchette" first came out, I remember that
it acquired quite a reputation as a particularly erratic piece of
mechanism, but for real mystery and _innate cussedness_, on general
principles, commend me to the indicator. Why, I have known an indicator
after registering a nice water bill, to deliberately and without
provocation commence taking it all off again, by going backward. This
crab-like maneuver the agent readily explained by saying the "ratchet
had turned over," but even he was unable to show us how to make the
bills after these peculiar gyrations. I also find that it is quite a
favorite amusement for indicators to stop entirely, like a balky horse,
after which no amount of persuasion will bring them to a realizing sense
of their duty.
Even at the best, these indicators are very apt to get out of order,
necessitating greater watchfulness in supplying elevators than for any
other purpose for which water is furnished.
Accidents in connection with the use of elevators are common throughout
the country, and in Kansas City had, until within a short time, become
of altogether too frequent occurrence. The great cause of this I believe
to be due to the fact that the parties who usually operate elevators
are the very ones who know least about them; the corrosion of pistons,
crystallization and oxidation of cables, and many other disorders common
to elevators, being matters they do not comprehend. The frequency
and fatality of these accidents in Kansas City finally led the city
authorities to appoint an Elevator Inspector, who is under heavy bond,
and whose duty is to examine every elevator at least once a month, and
to grant license to run only such as he deems in safe condition. Thus
far since the establishment of this office we have had no serious
accidents, which leads me to the belief that in most cases a monthly
examination will discover in time the causes of many terrible
casualties; also that it is not safe to operate elevators unless so
inspected by some competent person.
The hatchways of elevators in large buildings are points greatly feared
by firemen. They well know that when a fire once reaches this shaft, it
takes but a moment for it to be carried from floor to floor, until the
building is soon past saving. Although this great danger is well known,
it is the exception rather than the rule to provide elevators with
fire-proof hatches. A properly constructed elevator should, it seems
to me, be provided with hatches, or better still, built within brick
fire-proof walls, with openings to be kept closed when not in use. In
this way costly buildings, valuable merchandise, and many lives would be
saved from fire every year.
Although considerable has been said on the subject of elevators, I am
aware that the ground has not been covered, and that difficulties have
been pointed out more than remedies suggested. There is much yet to be
brought out by the engineers, to whom the subject more properly belongs.
In the mean time, although elevators claim many of the objectionable
features in the business of water supply, most of them are not of a
nature that should condemn their use; on the contrary, I hope that
with the joining of our experience there will be an improvement in the
methods of their supply. Inasmuch as they must be furnished with water,
all that can be done is to adopt such rules and fix such rates as will
compensate in some degree for their objectionable qualities.
WATER MOTORS.
My remarks on this subject I trust will be more to the have been point
than they upon the questions already discussed. Certainly my ideas are
more decided, so far at least as supplying water motors is concerned.
In many respects I believe water motors furnish as nearly perfect power
as it is possible to attain. A motor, for instance, properly connected
and supplied by the even pressure from a reservoir is probably the most
reliable and steady power known, not excepting the most improved and
costly steam engines. The convenience and little attendance necessary in
operating make them especially desirable for many purposes. Where only
small power is required, or even where considerable power for only
occasional use is desired, they are particularly well adapted, and
can be driven at small expense. Even for greater power they possess
advantages over steam engines which, to a considerable extent,
compensate for the large water rates that ought to be paid for their
supply. These advantages are in the first cost of a motor, as compared
with a steam engine, the saving in attendance and fuel, the convenience
and cleanliness, and in some cases a saving in insurance by reason of
their being no fire risks attendant upon its use. At just what point
steam becomes preferable, however, is a question depending considerably
upon water rates, but to some extent on other circumstances, leaving
it largely a question of judgment. As with elevators, there are
difficulties involved in their supply that unless carefully guarded make
water motors anything but a desirable source of revenue. How often is
the argument advanced: "Why, I only use water for a quarter of an inch
jet!" Showing how little people who use motors or elevators or fountains
realize the quantity of water they consume. This class of consumers may
be placed on one footing, to wit, a class who, in spite of the fact that
they are supplied with water for much less than any other, feel that
they are imposed upon, and cannot be made to think otherwise.
Though not as large as for elevator supply, water motors require liberal
openings in the mains, and frequently the fault of having too small
supply pipes is sought to be remedied by openings in the water mains
much larger than needful. A table prepared by an engineer who had given
the matter study, or by some motor manufacturer, showing the size of
taps, or openings, for the proper supply of motors, with the various
jets, under different pressures, would be of general use to water-works
people. In order to use water to the best advantage, the full pressure
in the main, so far as practicable, should be had at the jet, but in
order to accomplish this it is not necessary to use as large taps as are
ordinarily demanded, but to provide supply pipes of sufficient capacity
to deliver the water to the point of discharge with the least possible
friction. Lately this theory has been put in practice to some extent by
us, and the result has shown that in this manner we are able to supply
motors through smaller taps than beforehand with as satisfactory
results.
It is a general practice throughout the country to make annual or
monthly rates for water motors, and from my observation I believe I can
safely venture the assertion that in three-quarters of the cases the
rates charged will not equal 50 per cent. of the lowest meter rates in
force in these places. Although the Kansas City Water-Works has not
perhaps been generally accorded the reputation of being the most liberal
"monopoly" in the country, still I have had occasion at times to make
some such claims as an inducement to its generous support. But with all
its liberality, I am free to say that we cannot begin to meet the rates
for motors that parties claim to have paid almost everywhere else.
The St. Louis Water-Works, where the rates are substantially the same as
in Kansas City, have been quoted as having the following motor rates,
but whether correct or not my inquiries have failed to determine:
"On the supposition that motors are to be used ten hours per day for 300
days per year, motors are assessed for--
___________________________________
1/4 inch jets | $120 per annum. |
3/8 " | 198 " " |
1/2 " | 300 " " |
----------------+-----------------+
These rates based upon a charge of 50 cents per 1,000 gallons."
From Col. Flad's Report as Engineer of Public Works, May 1, 1876, p.70,
it is found that with 42 pounds pressure a 1/2 inch orifice will discharge
2,160 gallons per hour, 21,600 gallons in 10 hours, or 6,480,000 gallons
in 300 days, which at 20 cents per 1,000 gallons would amount to $1,296,
for which they assess the rate $300. From all of which I would conclude
that there must be a lack of harmony somewhere between the engineering
and office departments.
I have made some estimates myself for water motors, basing rates upon
the number of hours it was claimed the motors would be in use, and
afterward supplied the same motors by meter measurement; in every case
found that at least twice as much water was used as had been estimated.
Although estimates were carefully made upon what was believed to be
a reliable basis, these repeated similar results have led me to the
conclusion that the only way to supply motors is to make it an object to
the users of them to be economical. In other words, I believe the way to
supply water motors is upon an estimate that they will run 24 hours per
day and 365 days per year, or, more properly still, supply them only by
meter measurement. At all events this is henceforth my policy; or, in
other words, "on this rock I stand," believing it the only equitable way
out of this difficulty.
That class of motors or water engines operated by water pressure in
close cylinders upon pistons as with steam in a steam engine, I believe
could be easily supplied by measurement of water without a meter. This
could be accomplished by the use of "revolution counters" or indicators,
as the amount of water required per revolution could be readily
determined, and when once computed the cylinders would measure out the
water as accurately as a meter. The only objection to this plan is the
expense of counters, which is considerable; and as to indicators, it may
have been observed that I have little faith in their reliability. With
cheap revolution this class of motors would be free from many of the
objections raised in regard to motors generally.
The practical conclusion that I would draw from a consideration of
this subject is that the question of whether the supply of hydraulic
elevators and motors is desirable in its effects upon the water supply
is one that hinges so delicately upon their being carefully governed,
connected, and restricted, that while on the one hand they may be made
the source of large profit, and at the same time a public benefit, on
the other hand, unless all the details of their supply be carefully
guarded by the wisest rules and greatest watchfulness, their capacities
for waste are so great and the rates charged necessarily so low, that
they may become the greatest source of loss with which we have to
contend. I therefore trust that this discussion will be continued until
an interest is felt that will result in our all receiving much useful
information upon two most important factors of our business.
As this paper has been long for the information contained, I will close
with the earnest wish that it may at least be of service in bringing
these important but often neglected subjects to the attention of the
thinking and intelligent body of men, of whom many have had much longer
and more general experience in relation to these matters, and whose
views when expressed will consequently be of more interest and have
greater weight. Thus as a result may we all derive the benefit of
whatever useful information there is to be gained by this annual
interchange of experiences in the all-important business of public water
supply.
* * * * *
WATER SUPPLY OF SMALL TOWNS.
We now describe the new waterworks lately erected for supplying the town
of Cougleton, Cheshire. The population is about 12,000, and the place is
a seat of the silk manufacture. After various expensive plans had been
suggested, in the year 1879 a complete scheme for the supply of the town
with water was devised by the then borough surveyor, Mr. Wm. Blackshaw,
now borough surveyor of Stafford. These we now illustrate above by a
general drawing, and a separate drawing of the tower. With respect
to the mechanical arrangements, the Corporation called in Mr. W. H.
Thornbery, of Birmingham, consulting engineer, to decide on the best
design of those submitted, and this, with modifications made by him, was
carried out under his inspection. The water, for the supply by pumping,
is obtained from springs situated at the foot of Crossledge Hill, about
a mile from the town. It does not at present require filtering, but
space enough has been allowed for the construction of duplicate
filtering beds without in any way interfering with the present
appliances. These filter beds are shown in our perspective illustration,
but they are not yet built or required.
[Illustration: WATER SUPPLY OF SMALL TOWNS--CONGLETON WATERWORKS.]
The waterworks are situated very near the springs, from which they are
only separated by a road, under which the collecting pipes run. There
are two circular collecting tanks of brickwork, two pumping wells,
engine-house, boiler-house, chimney stack, and engine-driver's
dwelling-house, all inclosed by a wall. On the top of Crossledge Hill is
erected a circular brick water tower 35 ft. high to the underside of the
service tank, which is of cast iron 30 ft. internal diameter, supported
on rolled girders. The tank is capable of containing 50,000 gallons
of water, and it is provided with the usual rising and service mains,
overflow and washout pipes. There is an arrangement for pumping direct
into the mains in case the tank should require cleaning or repairing.
The pumping machinery is in duplicate, and each set consists of a
horizontal condensing engine, with cylinder 18 in. diameter, stroke 30
in., fitted with Meyer's expansion gear, governor, fly-wheel 12 ft.
diameter, weighing 4 tons, jet condenser with a single acting vertical
air pump, situated below the engine room floor, and between the end
of the cylinder and the main pump. Each main pump is 10 in. diameter,
horizontal, double-acting, worked by a prolongation backward of the
piston-rod. The valves and seats are of gun metal, 81/2 in. diameter. The
capacity is 350 gallons per minute, raised 206 ft. The air vessel is 21
in. internal diameter and 6 ft. high, and is fitted with a hand pump for
renewing the supply of air if necessary. The rising main from the air
vessel to the service tank is 9 in. diameter, and 307 yards long, laid
up the steep slope of the hill on which the water tower is built. The
boilers, two in number, are of the ordinary Cornish single-flued type, 5
ft. diameter by 18 ft. long, with flue 2 ft. 9 in. diameter, with three
Galloway tubes. They were made by Messrs. Hill & Co., of Manchester. The
engines and pumps were made by Mr. Albert Scragg, of Congleton, and the
brick, stone, and builder's work was executed by Mr. Thomas Kirk. The
waterworks were opened in the autumn of 1881, and since then have
constantly afforded an abundant supply of water. There is also an
independent gravitation system, also arranged by Mr. Blackshaw, for
supplying an outlying part of the town. The cost of the works was
exceedingly moderate, being not more than L12,000, including the water
mains for distribution.
PROCESS FOR SOFTENING HARD WATER.
The available water of many villages and small towns is that of the
chalk beds, but it is invariably very hard, and should be softened. We
have received so many inquiries respecting a simple means of carrying
out Clarke's water-softening process, that the following description
of a set of apparatus devised for this purpose by Messrs. Law and
Chatterton, MM.I.C.E., may interest many besides those who contemplate
the construction of small waterworks supplied by the chalk springs.
The apparatus, as made in various sizes by Messrs. Bowes, Scott,
and Read, of Broadway-chambers, Westminster, we illustrate by the
accompanying engravings.
_Softening hard water_.--The disadvantages attending the use of hard
water either for drinking purposes, steam generation, lavatory purposes,
and for many manufacturing purposes, are well known, but as there are
several methods of softening waters which are hard in different degrees
by different substances, we may be pardoned if we here reproduce, for
the convenience of some of our readers, a few passages from the sixth
report of the River Pollution Commission, 1874, pages 21 and 201-16,
which give some very valuable information on the relative merits of
hard and soft waters in domestic and trade uses. "Some of the mineral
substances which occur in solution in potable waters communicate to the
latter the quality of hardness. Hard water decomposes soap, and cannot
be efficiently used for washing. The chief hardening ingredients are
salts of lime and magnesia. In the decomposition of soap these salts
form curdy and insoluble compounds containing the fatty acids of
the soap and the lime and magnesia of the salts. So long as this
decomposition goes on the soap is useless as a detergent, and it is
only after all the lime and magnesia salts have been decomposed at the
expense of the soap, that the latter begins to exert a useful effect.
As soon as this is the case, however, the slightest further addition of
soap produces a lather when the water is agitated, but this lather is
again destroyed by the addition of a further quantity of hard water.
Thus the addition of hard water to a solution of soap, or the converse
of this operation, causes the production of the insoluble curdy matter
before mentioned. These facts render intelligible the process of washing
the skin with soap and hard water. The skin is first wetted with the
water and then soap is applied; the latter decomposes the hardening
salts contained in the small quantity of water with which the skin
is covered, and there is then formed a strong solution of soap which
penetrates into the pores, and now the lather and impurities which it
has imbibed require to be removed from the skin by wiping the lather off
with a towel or by rinsing it away with water. In the former case the
pores of the skin are left filled with soap solution; in the latter they
become clogged with the greasy, curdy matter which results from the
action of the hard water upon the soap solution which had previously
gained possession of the pores of the cuticle. As the latter process of
removing the lather is the one universally adopted, the operation of
washing with soap and hard water is analogous to that used by the dyer
and calico printer for fixing pigments in calico, woolen, or silk
tissues. The pores of the skin are filled with insoluble greasy and
curdy salts of the fatty acids contained in the soap, and it is only
because the insoluble pigment produced is white, or nearly so, that so
repulsive an operation is tolerated. To those, however, who have been
accustomed to wash in soft water, the abnormal condition of skin thus
induced is for a long time extremely unpleasant.
Of the hardening salts present in potable water, carbonate of lime is
the one most generally met with, and to obtain a numerical expression
for this quality of hardness a sample of water containing 1 lb. of
carbonate of lime, or its equivalent of other hardening salts, in
100,000 lb.--10,000 gallons--is said to have 1 deg. of hardness. Each degree
of hardness indicates the destruction and waste of 12 lb. of the best
hard soap by 10,000 gallons of water when used for washing. Hard water
frequently becomes softer after it has been boiled for some time. When
this is the case, a portion at least of the original hardening effect is
due to the bicarbonate of lime and magnesia. These salts are decomposed
by boiling into free carbonic acid, which escapes as gas, leaving
carbonates of lime and magnesia; the latter being nearly insoluble in
water, ceases to exert more than a very slight hardening effect, and
produces a precipitate. As the hardness resulting from the carbonates
of lime and magnesia is thus removable by boiling the water, it is
designated temporary hardness, while the hardening effect which is due
chiefly to the sulphates of lime and magnesia, and cannot be got rid of
by boiling, is termed permanent hardness. The total hardness of water
is therefore commonly made up of temporary and permanent hardness.
A constant supply of hot water is now almost a necessity in every
household, but great difficulties are thrown in the way of its
attainment by the supply of hard water to towns forming thick calcareous
crusts in the heating apparatus.
Waters with much temporary hardness are most objectionable in this
respect, and the evil is so great where the heating is effected in a
coil of pipe, as practically to prevent, in towns with hard water, the
use of this most convenient method of heating water. The property of
being softened by boiling which temporarily hard water possesses is not
of much domestic use, for water is, as a rule, either not raised to a
sufficiently high temperature or not kept at it for a long enough time.
Seeing then the disadvantages attendant on the use of hard water, it
remains to be considered how best to soften it. Four processes are known
to the arts. They are: Distillation, carbonate of soda, boiling, lime.
Of these processes the first and second are the most effective, but
owing to their expense are not applicable on a large scale. The third
and fourth processes are efficient only with certain classes of water,
rendered hard by the presence of the bicarbonate of lime, magnesia,
or iron. The fourth is, however, a very cheap process, and is easily
applicable to the vast volumes of water supplied to large cities,
provided the hardening ingredients are of the character described.
_Softening by distillation_.--By evaporation, water is completely
separated from all fixed saline matters, and consequently from all
hardening matters. Distilled water, however, has a vapid and unpleasant
taste, due partly to deficient aeration and partly to the presence of
traces of volatile organic matter; and though filtration through animal
charcoal will remove this, and the aeration can begin chemically, the
process is too expensive, except in certain cases, as on board ship, or
at military or naval stations where no potable water exists.
_Softening by carbonate of soda_.--The hardness of water, as already
explained, being principally due to the presence in solution of
bicarbonates and sulphates of lime and magnesia, can be reduced by
addition of carbonate of soda, which decomposes these salts slowly in
cold water but quickly in hot, forming insoluble compounds of lime and
magnesia, which are slowly precipitated as a fine mud, leaving the water
charged, however, with a solution of bicarbonate and sulphate of soda.
This process, on account of expense, is only applicable on a small scale
to the water for laundry purposes, as the water acquires an unpleasant
taste from the presence of the soda salts. For laundry purposes it is,
however, valuable, as it effects a great saving of soap.
_The softening of water by boiling_.--That portion of the hardness of
water due to the presence of bicarbonate of lime, magnesia, or iron, is
corrected by boiling the water for half an hour. During ebullition the
bicarbonates, which are soluble, become carbonates, which are insoluble,
giving off their carbonic acid as gas, rendering--by the precipitate
produced, but not allowed in a boiler time to settle--the water muddy,
but incapable of decomposing soap. To raise the temperature of 1,000
gallons of water to the boiling point and to maintain it for half an
hour requires the consumption of about 21/2 cwt. of coal, or by the
wasteful appliances found in households, probably three times that
amount. Softened by boiling, then, 1,000 gallons of water would cost
about 7s. 6d., while the cost of softening the same amount by soap is
9s., at L2 6s. 6d. per cwt.
_The softening of water by lime_.--The economy which carbonate of
soda exhibits in comparison with soap as a softening material is far
surpassed by the use of lime. Lime costs about 8d. per cwt., and this
weight of lime will soften the same volume of water as would require the
use of 201/4 cwt. of soap. From the above it is evident--so soon as it is
conceded that there is an advantage in using soft water--that the lime
process is by far the most economical. Besides the chemical action
affecting the hardness, it has another most important mechanical action,
in consequence of the weight of each particle composing the precipitate
produced by it. These particles during subsidence become attached to the
almost microscopical organic impurities present in all river water, and
drag them down to the bottom of the settling tank, whereby the water is
rendered, after some eight hours, clear as crystal. The average cost of
the water supplied by the leading metropolitan water companies is L10
10s. 93/4d. per million gallons. The charge made by the companies to
consumers is about 6d. per 1,000 gallons, or L25 per million gallons.
It has been found that water can on a large scale be softened from 14 deg.
hardness to 5 deg. at a cost of 20s. per million gallons--that is, 10 per
cent. on the cost of the water to the companies, or 4 per cent. as the
price charged to consumers. This estimate does not take into account the
value of the precipitated chalk, which has a market price, and is used
for many purposes, being, in fact, whiting of the purest quality. The
operations necessary in Clarke's process are four in number: (1) The
preparation of milk of lime; (2) the preparation of a saturated solution
of lime; (3) the mixture of this solution with the water to be softened;
(4) the classification of the softened water by the separation of
the precipitated substances Messrs. Law and Chatterton effect these
processes by simple mechanical means which are so far automatic that
they only require the presence of a person, without technical knowledge,
once in each twenty-four hours. No filtering medium whatever is
required, which is a great advantage for the following reasons: (1)
Filtering materials require periodical cleaning and renewal, which
not only occasion much trouble and mess, but are also frequently
inefficiently performed. (2) Experience has shown that the filtering
material, whether cloth, charcoal, or other substance, is extremely
liable to become mouldy or musty, which makes the wafer both unwholesome
and unpalatable. This system is especially adapted for small water
supplies and for use in country houses, there being no operation to
perform requiring either technical, chemical, or mechanical knowledge,
nor producing dust or dirt.
[Illustration: Fig. 1.--LAW AND CHATTERTON'S WATER-SOFTENING APPARTUS.]
The following is a description of this apparatus as fitted at the
Hoo, Luton, Bedfordshire, for the supply of Mr. Gerard Leigh's house,
grounds, and home farm. The mixing of the lime and the subsequent
stirring of the water is effected by water power obtained from a
turbine. The whole of the apparatus and tanks occupy a space 60 ft.
square, 3,600 ft. area, and soften a daily supply of 50,000 gallons.
[Illustration: Fig. 2]
A pump driven from the turbine forces the water to a reservoir in the
park and on to the house, an ingenious automatic arrangement worked by
the overflow from the cistern throwing the pump out of gear when the
tank is full. A, B, and C. Figs. 1 to 6 herewith, are three tanks in
which the water remains to be softened, each capable of holding one
day's supply. D and E are two smaller tanks in which the lime water is
prepared; X is the automatic valve apparatus by which the connections
between the several tanks are effected in the order and at the times
required; H and H show the positions in which two pumps should be
placed, the former for pumping unsoftened water into the tanks, the
latter to pump the softened water into the supply cistern. J is the pipe
from the well or other source of supply--in case the supply is at a
higher level, one pump can be dispensed with. The operation consists in
adding to the water to be softened a certain quantity of lime water,
depending upon the degree of hardness, and in then allowing the mixture
to rest in a state of perfect quiescence until the whole of the lime has
been deposited and the water has become perfectly clear. The tank, A,
has been filled with unsoftened water. Tank B contains the water
and lime in process of clarification by subsidence after mechanical
agitation by the screw. Tank C contains the softened water--and the
precipitate--in process of removal for consumption. The mode of working
is as follows: The milk of lime, prepared by slaking new lime in a
"Michele mixer"--not shown. One of the tanks, D, having been filled with
softened water, run by gravity from one of the tanks, A, B, or C, the
requisite amount of milk of lime is allowed to flow into it from the
lining machine, and the whole having been thoroughly mixed by the patent
agitator, G, is left in a quiescent state for some hours, when the
superabundant lime falls to the bottom, and the tank contains a
perfectly clear and saturated solution of lime. The requisite quantity
of lime water is then suffered to flow by gravity into whichever of the
three tanks is empty. In the mean while, the softened water is being
withdrawn by pumping or gravitation, as the case may be, from the tank
C, until, upon the water being lowered to within a certain distance of
the bottom, an automatic arrangement shifts the valve, X, so that the
supply then commences from B, the unsoftened water flows into C, and
the water is in process of clarification in A, and thus the operation
proceeds continuously. Where the water can be supplied by gravitation,
and the tanks can be placed at a sufficient elevation to command the
service cistern, no pumps are required, the softening process, in fact,
in no way necessitating pumping. The space occupied by the whole of the
tanks and apparatus is 60 ft. square, 3,600 ft. area, and softens 50,000
gallons per day. For the daily softening of quantities less than 1,000
gallons, the tanks are made of galvanized sheet iron, and the whole
apparatus and tanks are self-contained, so as only to require the making
of the necessary connections with the existing supply and delivery
pipes, and fixing in place. No expensive foundations are required, and
the entire cost of an apparatus--see Figs. 2, 3, 4, 5, and 6--capable of
softening 500 gallons per day is about L75. Annexed is a more detailed
description of the manner of fixing and working the smaller apparatus.
[Illustration: Fig. 3]
The tank must, of course, be set up perfectly level. The pipe from the
source of supply--in the present case from the hydraulic ram--must
be attached to the upper three way cock at A, on the accompanying
engravings, and the pipe to supply softened water is to be connected
to the lower three-way cock at B, and should be led into the elevated
cistern with a ball cock so as to keep it always filled. The three ball
cocks in C, D, and E should be adjusted to allow the tanks to fill to
within 3 in. of the top. The nuts at the upper extremity of the three
rods, F, G, and H, should be so adjusted that when the water in the
several tanks has been drawn down to within 15 in. of the bottom the
rocking shaft, I I, is drawn down and the vertical rod, J, lifted so as
to allow the wheel, K, and spindle, L, to revolve by the action of the
weight, M. The length of the chain is such that when the weight, M,
rests upon the floor the face of the raised rim on the wheel, K, should
not quite touch the rod, J, and if necessary, a thin packing should be
put for the weight to drop upon. The lime to be used should be pure
chalk lime free from clay, mixed with water to a smooth, creamy
consistency, and then poured into the small tank, N. This tank should
then be filled with water to within 3 in. of the top, and the small air
pump worked until the lime has become thoroughly mixed and diffused
throughout the water. Care must be taken that previous to filling the
tank the float, O, is raised up, as shown by the dotted lines in Fig. 3.
After the lime has been thoroughly mixed it should be left for at
least eight hours for the superabundant lime to subside, leaving the
supernatant fluid a perfectly clear saturated solution of lime. At the
end of this time the float, O, should be lowered, so that it may float
upon the lime water, and the three-way cock, P, should be turned in such
a position as to allow the contents of the tank, N, run into the
tank, Q, until the necessary quantity has been supplied, the mode of
determining which is hereinafter described.
[Illustration: Fig. 4]
The spindle, L, should then be turned into the position which allows the
water from the source of supply to be discharged into the tank, Q, the
float, R, having first been raised into the position shown in Figs. 2
and 5. A second quantity of the lime should now be added to the tank, N,
mixed with water, and after agitation, another eight hours allowed for
the contents of both the tanks, Q and N, to subside. At the end of
this time the three-way cock, P, should be turned through a third of
a circle, so as to discharge the lime water into the tank, S; and the
spindle, L, should be turned in the contrary direction to the hands of a
watch through the third of a circle, so as to allow the water from the
source of supply to be discharged into the tank, S, care being taken as
before to raise the float, T, out of the water. A third quantity of lime
must be added to the tank, N, and now mixed with water to be drawn from
the tank, Q, by the tap, U, and after agitation again left for eight
hours to subside. The float, R, may now be lowered into the water in the
tank, Q, when it will be found that the clear softened water contained
in the tank, Q, will be discharged through the pipe attached to the
bottom of the three way tap, B. The weight, M, must now be lifted about
5 in., so as to allow the ring at the end of the chain to be moved back
to the next stud on the wheel, K. The lime water in the tank, N, must
next be discharged into the tank, V, and then another quantity of lime
must be added to the tank, N, and filled up with softened water from the
tank, S, by means of the tap, W, and after being duly agitated and left
to subside. As soon as the softened water from the tank, Q, has been
drawn down to within 15 in. of the bottom, the rod, H, will move the
rocking shaft, I, and lift the rod, J, so releasing the wheel, K, and
allowing the weight, M, to descend and turn the spindle, L, and the
upper and lower three-way cocks through a third of a circle; the effect
of which movement will be to continue the supply of softened water from
the tank, S, and to fill up the tank, V, with water from the source of
supply.
[Illustration: Fig. 5]
The apparatus will now be in the condition to afford a regular supply
of softened water; all that will be necessary to insure its continuous
action will be that at certain stated intervals dependent upon the
rapidity with which the water is used--but which interval should not
be less than eight hours--the following things should be done: (1) The
float must be raised out of the tank last emptied. (2) The float must be
lowered into the tank last filled. (3) The weight, M, must be raised,
and the ring of the chain shifted to the next stud on the wheel, K. (4)
The clear lime water found in the tank, N, must be turned into the tank
last emptied. (5) The requisite quantity of lime must be put into the
tank, N. (6) The requisite quantity of water must be drawn off from the
tank last filled into the tank, N. (7) The contents of tank, N, must be
thoroughly mixed by means of the air pump. The quantity of lime to be
used for each tankful of water must depend upon the hardness of the
water, 3/4 oz. being required for each tankful for each degree of
hardness. It is desirable, however, always to have an excess of lime in
the tank, N, so as to insure obtaining a saturated solution of lime.
When first mixed the contents of the tank, N, will have a creamy
appearance, but when the superabundant lime has subsided the supernatant
liquid will be a perfectly clear saturated solution of lime. Therefore,
in the first instance, 3 lb. of lime should be put into the tank, N, and
subsequently each time such a quantity of lime should be added as is
found to be necessary by the method hereinafter described. The quantity
of the saturated lime water to be run into each of the softening tanks,
Q, S, and V, will depend upon the hardness of the water. For every
degree of temporary hardness a depth of 1-6/10 in. of the contents of
the tank, N, will be required; so that if the water has 14 deg. of
temporary hardness, then 221/2 in. in depth of lime water must be run off
into each of the tanks, Q, S, and V. In the first instance an excess of
lime may be used, and the softened water tested by means of nitrate of
silver in the following manner: A solution of 1 oz. of nitrate of silver
in a pint of twice distilled water should be obtained. Having let two
or three drops of this solution fall on the bottom of a white tea cup,
slowly add the softened water; then if there be any excess of lime, a
yellow color will show itself, and the quantity of lime water used must
be reduced until only the faintest trace of color is perceptible.--_The
Engineer_.
[Illustration: Fig. 6]
* * * * *
IMPROVED WATER METER.
We annex illustrations of a meter designed by Mr. A. Schmid, of Zuerich,
and which, according to _Engineering_, is now considerably used on
the Continent, not only for measuring water, but the sirup in sugar
factories, in breweries, etc. It consists of a cast iron body containing
two gun-metal-lined cylinders, and connected by an intermediate chamber.
Round the body are formed two channels, one for the entrance and the
other for the discharge of the water, etc., to be measured. Within the
cylinder are placed two long pistons, provided with openings in such
a way that each piston serves as a slide valve to the other, the flow
being maintained through the ports in the connecting chamber. The
arrangement of openings in the piston is shown in Figs. 5, 6, 7, and the
intermediate passages in Figs. 1, 2, and 3. To the upper side of each
piston is attached a cross-head working on a disk placed at each end of
a horizontal shaft. To one of the disks is added a short connecting rod
that drives the spindle of a counter.
[Illustration: SCHMID'S WATER METER.]
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WASHING MACHINE FOR WOOL.
The washing machines in use for wool on the rake principle have during
the last few years experienced many improvements in the details of
their arrangement, which we have illustrated at different times in our
columns. The introduction of these improvements and alterations shows
that the washing of wool has attracted more attention on the part of
observant manufacturers and machine makers, and demonstrated at the same
time that the machines hitherto in use, with all their advantages, left
much to be desired in other respects. The main difficulty with all
washing machines for wool has been the avoidance of felting of the wool,
which tendency is increased by the use of warm water for washing and by
the agitation that some consider necessary for a thorough cleansing of
the wool and removal of the adhering impurities, but which agitation is
deprecated by others.
[Illustration: IMPROVED WOOL WASHING MACHINE.]
Referring to our different illustrations of improvements in this
direction, our subscribers will observe that the tendency of all these
has been to keep the wool floating in the water, and to apply all
mechanical appliances required for its cleansing and pressing as much as
possible while it is in this suspended condition. The success which the
different appliances and improvements mentioned by us have had when used
for the class of wool for which they are intended, has induced us to
look up any attempts in a similar direction which have been made on the
Continent, where the subject has attracted attention, as well as with
us. We therefore give the annexed illustration of a machine invented by
a German woolen manufacturer, which in many respects is a wide departure
from the acknowledged type in use in this country. As with the English
machines, the wool enters from a creeper at one end, passes through a
long trough, filled with water or lye, ascends an inclined plane, and
passes out through a pair of squeezing rollers. The invention mentioned
applies to the treatment in the trough which latter is shown in our
illustration at K. It has a second bottom, a little distance from a
false one, at K. The false bottom is traversed in its whole length by
an air pipe, communicating with the atmospheric air outside the trough.
From this longitudinal pipe other pipes branch off at right angles at
stated intervals, as shown in section in Fig. 2. These smaller pipes
contain a number of small perforations on their upper part, through
which the air ascends into the water in innumerable small bubbles. This
is one of the principal aims of the invention, for in ascending the
bubbles lift the wool more or less to the surface and tend to open it
out without the risk of doing so by any mechanical means liable to
produce felting. This is the same effect that is produced in many cases
so successfully in boiling. Instead of rakes the inventor has placed
four hexagonal drums into the trough, marked D, E, F, G. The flat parts
of these drums are made of perforated metal and set back a little. This
produces an alternate passing of the water into and out of them during
their revolution and consequent sucking and repulsing of the wool, which
also likewise agitates it. These drums are made wide at the entrance end
of the trough and gradually narrower toward the delivery end. The pipe,
V V, is the usual steam pipe for heating the water.
We have said before that the improvements introduced into the wool
washing machines nearer home have been of advantage for the wools for
which they are intended, and possibly the invention just described will
also be valuable in some cases.--_Tex. Manuf._
* * * * *
INCREASING THE ILLUMINATING POWER OF GASES, ETC.
By V. POPP, of Paris.
This invention relates to lighting by mixing air or other gaseous
supporter of combustion with illuminating or other hydrocarbon gas or
vapor, and burning the mixture (at a suitable pressure) in a burner of
special construction, shown in the accompanying illustrations.
[Illustration]
The burner is constructed as shown in Figs 1 and 2. It consists of a
central tube, i, screwing upon the pipe by which the gaseous mixture is
supplied. Upon this tube is screwed a cup, k, of metal or refractory
material which supports a cap, l, of fire-clay in the shape of a thimble
(or of other form, according to the intended use of the burner). The
flanged base of this cap is perforated with a ring of holes, m, as small
and numerous as possible, and the sides of the cap are pierced with
oblique perforations, n. The top of the tube, i, is provided with four
small projections, upon which rests a copper cone, o, soldered to the
tube at a point below the perforations in the base of the thimble. The
cone is perforated at its lower end with small holes, p, the sum of
whose areas is at least equal to the area of the tube. The thimble,
l, is surrounded by an envelope, q, of platinum wire netting or other
refractory material of the same form. The gaseous mixture arriving by
the pipe, i, escapes at the upper orifices, r, and passes down against
the interior surface of the cone, o, out at the orifices, p, and escapes
through the orifices in the cap, l, at which it is burned. The cap is
thereby raised to a high temperature; and the platinum wire sheath
becoming incandescent radiates the light. The gaseous mixture, by coming
first in contact with the copper cone and then with the refractory cap,
becomes raised to an exceedingly high temperature before it is consumed.
In the modified burner represented in Fig. 3, the metal cone and the
fire-cap are truncated. The tube, i, is provided with a number of small
perforations, r, at its upper end, the sum of whose areas is at least
equal to the area of the tube, and by which the gaseous mixture is
distributed within the chamber, k. Upon the upper closed end of the tube
is fixed a cup or inverted thimble, o, of fire-clay. A refractory cone,
l, surrounds this cup and rests by its base upon the cup. This flanged
base is perforated with small vertical holes, m, and upon it is fixed a
platinum wire cage or envelope, q. An annular space is left between the
cone and cup for the passage of the gaseous mixture, which, on escaping
from the orifices, r, passes over the exterior surface of o, the
interior of which is already heated by the flame which has not passed
through the wire gauze, and has been forced by the pressure of the
mixture into the interior of o. The gaseous mixture before passing
through the annular space thus attains such a temperature that on
escaping from the orifice its combustion is greatly promoted.
* * * * *
PREVENTING IRON FROM RUSTING.
In the present state of civilization the use of iron has reached a very
wide extension, and in a great number of cases iron is used where wood
or stone was formerly used. It is certainly an important question how
this metal can be protected under all circumstances against rust or
oxidation, so that the many costly iron structures may retain their
usefulness and strength, and be handed down uninjured to posterity.
Wherever bright iron comes into contact with air and moisture it
immediately begins to rust, and this rust is not content to continually
rob it of its substance in its persistent progress by scaling off the
surface, but at the same time it injures the remainder of the iron by
making it brittle. Attempts have hitherto been made to protect the iron
by covering it with other and less easily oxidizable metals. For this
purpose tin was first selected, then lead and zinc, and recently nickel.
Furthermore, earthy glazings and enamels, such as are used on stone
ware, have been applied to iron vessels, and they have already found
extensive use in the household. In most cases these coatings, either
metallic or vitreous, are inapplicable, either because they cannot be
applied or are too expensive, so that on a large scale recourse must be
had to paints made by mixing oils with metallic oxides, earths, etc.,
for protecting the surface of the iron from air and moisture.
It has been observed that iron does not rust in _dry_ air, not even in
dry oxygen. In like manner it frequently happens that unpainted iron,
such as weather vanes, fences, etc., is exposed to the air for a century
with very little injury, being covered with a thin coating of the
magnetic oxide (proto-sesquioxide), which acts as a protection and
prevents farther action. Hence it has been proposed to produce a layer
of this magnetic oxide on the surface artificially, and it was found
that superheated steam furnished the means for doing this. But it is not
to be supposed that such a process would find use on a large scale, and
besides this protection could only serve for iron tolerably exposed to
the open air and not for that in direct contact with carbonic acid and
water.
An interesting observation has been made on railways that the iron
rails, ties, bolts, etc., rust until the road begins to be used. Here we
must assume that anything made of iron is more inclined to rust when at
rest than if occasionally caused to vibrate, when an electrical action
probably comes into play and decreases the affinity of iron for oxygen.
In tearing down old masonry iron bonds and clamps are often found which
are as free from rust, so far as they are covered with mortar, as they
were the day they left the blacksmith's hands. A French engineer met
with such a phenomenon when he uncovered the anchor plates of several
chain bridges which had been built about thirty years. Where the anchors
were covered with the fatty lime mortar of the masonry they showed no
traces of rust, but the prolongations of the anchors in empty spaces
were rusted to such an extent that they were only one-third of their
original thickness.
It has been repeatedly observed that iron does not rust in water in
which are dissolved small quantities of caustic alkalies or alkaline
earths, which neutralize every trace of acid. It seems that these
experiences are the basis of A. Riegelmann's (Hanau) new protection
against rust. The paint that he uses contains caustic alkaline earths
(baryta, strontia, etc.), so that the iron is in a condition similar to
the iron anchors of the chain bridges that were embedded in lime mortar.
Although a paint is not thick enough to inclose so much alkali as the
masonry did that the iron was embedded in, nevertheless the alkaline
action will make itself felt as long as the coating has a certain
consistence. Under all circumstances, however, these new paints will
be free from active acids, which is more than can be said of our iron
paints hitherto in use. Besides this, the rust protector has such
a composition that it could serve its intended purpose without the
addition of any alkali. If experience confirms this claim, it will be an
interesting step forward in the preservation of iron, and contribute to
an extension in the use of iron.--_Polytechn. Notizblatt_.
* * * * *
[Illustration: SUGGESTIONS IN DECOTATIVE ART.--A CUPBOARD IN ITALIAN
WALNUT WITH DARKER PANELING.--_From The Workshop_.]
* * * * *
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