Scientific American Supplement No. 360, November 25, 1882
by
Various
Part 2 out of 3
proper strength, will make a perfect liniment.
_Linimentum Calcis_.--Cotton seed oil is not at all adapted to making
this liniment. It does not readily saponify, separates quickly, and it
is almost impossible to unite when separated.
_Linimentum Camphorae_.--Cotton seed oil is far superior to olive oil in
making this liniment, it being a much better solvent of camphor. It has
not that disagreeable odor so commonly found in the liniment.
_Linimentum Chloroformi_.--Cotton seed oil being very soluble in
chloroform, the liniment made with it leaves nothing to be desired.
_Linimentum Plumbi Subacetatis_.--When liq. plumbi subacet. is mixed
with cotton seed oil and allowed to stand for some time the oil assumes
a reddish color similar to that of freshly made tincture of myrrh. When
the liquor is mixed with olive oil, if the oil be pure, no such change
takes place. Noticing this change, it occurred to me that this would be
a simple and easy way to detect cotton seed oil when mixed with olive
oil. This change usually takes place after standing from twelve to
twenty-four hours. It is easily detected in mixtures containing five
per cent., or even less, of the oils, and I am convinced, after making
numerous experiments with different oils, that it is peculiar to cotton
seed oil.--_American Journal of Pharmacy_.
* * * * *
THE FOOD AND ENERGY OF MAN.
[Footnote: From a lecture delivered at the Sanitary Congress, at
Newcastle-on-Tyne, September 28, 1882.]
By PROF. DE CHAUMONT, F.R.S.
Although eating cannot be said to be in any way a new fashion, it has
nevertheless been reserved for modern times, and indeed we may say the
present generation, to get a fairly clear idea of the way in which
food is really utilized for the work of our bodily frame. We must not,
however, plume ourselves too much upon our superior knowledge, for
inklings of the truth, more or less dim, have been had through all ages,
and we are now stepping into the inheritance of times gone by, using the
long and painful experience of our predecessors as the stepping-stone
to our more accurate knowledge of the present time. In this, as in many
other things, we are to some extent in the position of a dwarf on the
shoulders of a giant; the dwarf may, indeed, see further than the giant;
but he remains a dwarf, and the giant a giant.
The question has been much discussed as to what the original food of man
was, and some people have made it a subject of excited contention. The
most reasonable conclusion is that man is naturally a frugivorous or
fruit-eating animal, like his cousins the monkeys, whom he still so
much resembles. This forms a further argument in favor of his being
originated in warm regions, where fruits of all kinds were plentiful. It
is pretty clear that the resort to animal food, whether the result of
the pressure of want from failure of vegetable products, or a mere taste
and a desire for change and more appetizing food, is one that took place
many ages ago, probably in the earliest anthropoid, if not in the latest
pithecoid stage. No doubt some advantage was recognized in the more
rapid digestion and the comparative ease with which the hunter or fisher
could obtain food, instead of waiting for the ripening of fruits in
countries which had more or less prolonged periods of cold and inclement
weather. Some anatomical changes have doubtless resulted from the
practice, but they are not of sufficiently marked character to found
much argument upon; all that we can say being that the digestive
apparatus in man seems well adapted for digesting any food that is
capable of yielding nutriment, and that even when an entire change is
made in the mode of feeding, the adaptability of the human system
shows itself in a more or less rapid accommodation to the altered
circumstances.
Food, then, is any substance which can be taken into the body and
applied to use, either in building up or repairing the tissues and
framework of the body itself, or in providing energy and producing
animal heat, or any substance which, without performing those functions
directly, controls, directs, or assists their performance. With this
wide definition it is evident that we include all the ordinary articles
recognized commonly as food, and that we reject all substances
recognized commonly as poisons. But it will also include such substances
as water and air, both of which are essential for nutrition, but are not
usually recognized as belonging to the list of food substances in the
ordinary sense. When we carry our investigation further, we find that
the organic substances may be again divided into two distinct classes,
namely, that which contains nitrogen (the casein), and those that do not
(the butter and sugar).
On ascertaining this, we are immediately struck with the remarkable fact
that all the tissues and fluids of the body, muscles (or flesh),
bone, blood--all, in short, except the fat--contain nitrogen, and,
consequently, for their building up in the young, and for their repair
and renewal in the adult, nitrogen is absolutely required. We therefore
reasonably infer that the nitrogenous substance is necessary for this
purpose. Experiment has borne this out, for men who have been compelled
to live without nitrogenous food by dire necessity, and criminals on
whom the experiment has been tried, have all perished sooner or later in
consequence. When nitrogenous substances are used in the body, they
are, of course, broken up and oxidized, or perhaps we ought to say more
accurately, they take the place of the tissues of the body which wear
away and are carried off by oxidation and other chemical changes.
Now, modern science tell us that such changes are accompanied with
manifestations of energy in some form or other, most frequently in
that of heat, and we must look, therefore, upon nitrogenous food
as contributing to the energy of the body in addition to its other
functions.
What are the substances which we may class as nitrogenous. In the first
place, we have the typical example of the purest form in _albumin_,
or white of egg; and from this the name is now given to the class of
_albuminates_. The animal albuminates are: Albumin from eggs, fibrin
from muscles, or flesh, myosin, or synronin, also from animals, casein
(or cheesy matter) from milk, and the nitrogenous substances from blood.
In the vegetable kingdom, we have glutin, or vegetable fibrin, which is
the nourishing constituent of wheat, barley, oats, etc.; and legumin,
or vegetable casein, which is the peculiar substance found in peas and
beans. The other organic constituents--viz., the fats and the starches
and sugars--contain no nitrogen, and were at one time thought to be
concerned in producing animal heat.
We now know--thanks to the labors of Joule, Lyon Playfair, Clausius,
Tyndall, Helmholtz, etc.--that heat itself is a mode of motion, a form
of convertible energy, which can be made to do useful or productive
work, and be expressed in terms of actual work done. Modern experiment
shows that all our energy is derived from that of food, and, in
particular from the non-nitrogenous part of it, that is, the fat,
starch, and sugar. The nutrition of man is best maintained when he is
provided with a due admixture of all the four classes of aliment which
we have mentioned, and not only that, but he is also better off if he
has a variety of each class. Thus he may and ought to have albumen,
fibrine, gluten, and casein among the albuminates, or at least two of
them; butter and lard, or suet, or oil among the fats; starch of wheat,
potato, rice, peas, etc., and cane-sugar, and milk-sugar among the
carbo-hydrates. The salts cannot be replaced, so far as we know. Life
may be maintained in fair vigor for some time on albuminates only, but
this is done at the expense of the tissues, especially the fat of the
body, and the end must soon come; with fat and carbo hydrates alone
vigor may also be maintained for some time, at the expense of the
tissues also, but the limit is a near one, In either of these cases we
suppose sufficient water and salts to be provided.
We must now inquire into the quantities of food necessary; and this
necessitates a little consideration of the way in which the work of
the body is carried on. We must look upon the human body exactly as a
machine; like an engine with which we are all so familiar. A certain
amount of work requires to be done, say, a certain number of miles of
distance to be traversed; we know that to do this a certain number of
pounds, or hundredweights, or tons of coal must be put into the fire of
the boiler in order to furnish the requisite amount of energy through
the medium of steam. This amount of fuel must bear a certain proportion
to the work, and also to the velocity with which it is done, so both
quantity and time have to be accounted for.
No lecture on diet would be complete without a reference to the vexed
question of alcohol. I am no teetotal advocate, and I repudiate the
rubbish too often spouted from teetotal platforms, talk that is,
perhaps, inseparable from the advocacy of a cause that imports a good
deal of enthusiasm. I am at one, however, in recognizing the evils of
excess, and would gladly hail their diminution. But I believe that
alcohol properly used may be a comfort and a blessing, just as I know
that improperly used it becomes a bane and a curse. But we are now
concerned with it as an article of diet in relation to useful work, and
it may be well to call attention markedly to the fact that its use in
this way is very limited. The experiments of the late Dr. Parkes, made
in our laboratory, at Netley, were conclusive on the point, that beyond
an amount that would be represented by about one and a half to two pints
of beer, alcohol no longer provided any convertible energy, and that,
therefore, to take it in the belief that it did do so is an error.
It may give a momentary stimulus in considerable doses, but this is
invariably followed by a corresponding depression, and it is a maxim now
generally followed, especially on service, never to give it before or
during work. There are, of course, some persons who are better without
it altogether, and so all moderation ought to be commended, if not
enjoyed.
There are other beverages which are more useful than the alcoholic,
as restoratives, and for support in fatigue. Tea and coffee are
particularly good. Another excellent restorative is a weak solution
of Liebig's extract of meat, which has a remarkable power of removing
fatigue. Perhaps one of the most useful and most easily obtainable is
weak oatmeal gruel, either hot or cold. With regard to tobacco, it also
has some value in lessening fatigue in those who are able to take it,
but it may easily be carried to excess. Of it we may say, as of alcohol,
that in moderation it seems harmless, and even useful to some extent,
but, in excess, it is rank poison.
There is one other point which I must refer to, and which is especially
interesting to a great seaport like this. This is the question of
scurvy--a question of vital importance to a maritime nation. A paper
lately issued by Mr. Thomas Gray, of the Board of Trade, discloses the
regrettable fact that since 1873 there has been a serious falling off,
the outbreaks of scurvy having again increased until they reached
ninety-nine in 1881. This, Mr. Gray seems to think, is due to a neglect
of varied food scales; but it may also very probably have arisen from
the neglect of the regulation about lime-juice, either as to issue or
quality, or both. But it is also a fact of very great importance that
mere monotony of diet has a most serious effect upon health; variety
of food is not merely a pandering to gourmandism or greed, but a real
sanitary benefit, aiding digestion and assimilation. Our Board of Trade
has nothing to do with the food scales of ships, but Mr. Gray hints that
the Legislature will have to interfere unless shipowners look to it
themselves. The ease with which preserved foods of all kinds can be
obtained and carried now removes the last shadow of an excuse for
backwardness in this matter, and in particular the provision of a large
supply of potatoes, both fresh and dried, ought to be an unceasing care;
this is done on board American ships, and to this is doubtless owing in
a great part the healthiness of their crews. Scurvy in the present
day is a disgrace to shipowners and masters; and if public opinion is
insufficient to protect the seamen, the legislature will undoubtedly
step in and do so.
And now let me close by pointing out that the study of this commonplace
matter of eating and drinking opens out to us the conception of the
grand unity of nature; since we see that the body of man differs in no
way essentially from other natural combinations, but is subject to
the same universal physical laws, in which there is no blindness, no
variableness, no mere chance, and disobedience of which is followed as
surely by retribution as even the keenest eschatologist might desire.
* * * * *
RATTLESNAKE POISON.
By HENRY H. CROFT.
Some time since, in a paper to which I am unfortunately unable to refer,
a French chemist affirmed that the poisonous principle in snakes, or
eliminated by snakes, was of the nature of an alkaloid, and gave a name
to this class of bodies.
Mr. Pedler has shown that snake poison is destroyed or neutralized
by means of platinic chloride, owing probably to the formation of an
insoluble double platinic chloride, such as is formed with almost if not
all alkaloids.
In this country (Texas) where rattlesnakes are very common, and persons
camping out much exposed to their bites, a very favorite anecdote, or
_remedia_ as the Mexicans cull it, is a strong solution of iodine in
potassium iodide.[1]
[Footnote 1: The solution is applied as soon as possible to the wound,
preferably enlarged, and a few drops taken internally. The common
Mexican _remedia_ is the root of the _Agave virginica_ mashed or chewed
and applied to the wound, while part is swallowed.
Great faith is placed in this root by all residents here, who are seldom
I without it, but, I have had no experience of it myself; and the
internal administration is no doubt useless.
Even the wild birds know of this root; the queer paisano (? ground
woodpecker) which eats snakes, when wounded by a _vibora de cascabel_,
runs into woods, digs up and eats a root of the agave, just like the
mongoose; but more than that, goes back, polishes off his enemy, and
eats him. This has been told me by Mexicans who, it may be remarked, are
not _always_ reliable.]
I have had occasion to prove the efficacy of this mixture in two cases
of _cascabel_ bites, one on a buck, the other on a dog; and it occurred
to me that the same explanation of its action might be given as above
for the platinum salt, viz., the formation of an insoluble iodo compound
as with ordinary alkaloids if the snake poison really belongs to this
class.
Having last evening killed a moderate sized rattlesnake--_Crotalus
horridus_--which had not bitten anything, I found the gland fully
charged with the white opaque poison; on adding iodine solution to a
drop of this a dense light-brown precipitate was immediately formed,
quite similar to that obtained with most alkaloids, exhibiting under the
microscope no crystalline structure.
In the absence of iodine a good extemporaneous solution for testing
alkaloids, and perhaps a snake poison antidote, may be made by adding a
few drops of ferric chloride to solution of potassium of iodide; this
is a very convenient test agent which I used in my laboratory for many
years.
Although rattlesnake poison could be obtained here in very considerable
quantity, it is out of my power to make such experiments as I could
desire, being without any chemical appliances and living a hundred miles
or more from any laboratory. The same may be said with regard to books,
and possibly the above iodine reaction has been already described.
Dr. Richards states that the cobra poison is destroyed by potassium
permanganate; but this is no argument in favor of that salt as an
antidote. Mr. Pedler also refers to it, but allows that it would not be
probably of any use after the poison had been absorbed. Of this I
think there can be no doubt, remembering the easy decomposition of
permanganate by most organic substances, and I cannot but think that the
medicinal or therapeutic advantages of that salt, taken internally, are
equally problematical, unless the action is supposed to take place in
the stomach.
In the bladder of the same rattlesnake I found a considerable
quantity of light-brown amorphous ammonium urate, the urine pale
yellow.--_Chemical News_.
Hermanitas Ranch, Texas.
* * * * *
THE CHINESE SIGN MANUAL.
[Footnote: Dr. D. J. Macgowan, in Medical Reports of China. 1881.]
Two writers in _Nature_, both having for their theme "Skin-furrows on
the Hand," solicit information on the subject from China.[1] As the
subject is considered to have a bearing on medical jurisprudence and
ethnology as well, this report is a suitable vehicle for responding to
the demand.
[Footnote 1: Henry Faulds, Tzukiyi Hospital, Tokio, Japan. W. J.
Herschel, Oxford, England.--_Nature_, 28th October and 25th November,
1880.]
Dr. Faulds' observations on the finger-tips of the Japanese have an
ethnic bearing and relate to the subject of heredity. Mr. Herschel
considers the subject as an agent of Government, he having charge for
twenty years of registration offices in India, where he employed finger
marks as sign manuals, the object being to prevent personation and
repudiation. Doolittle, in his "Social Life of the Chinese," describes
the custom. I cannot now refer to native works where the practice of
employing digital rugae as a sign manual is alluded to. I doubt if its
employment in the courts is of ancient date. Well-informed natives think
that it came into vogue subsequent to the Han period; if so, it is in
Egypt that earliest evidence of the practice is to be found. Just as the
Chinese courts now require criminals to sign confessions by impressing
thereto the whorls of their thumb-tips--the right thumb in the case of
women, the left in the case of men--so the ancient Egyptians, it
is represented, required confessions to be sealed with their
thumbnails--most likely the tip of the digit, as in China. Great
importance is attached in the courts to this digital form of signature,
"finger form." Without a confession no criminal can be legally executed,
and the confession to be valid must be attested by the thumb-print
of the prisoner. No direct coercion is employed to secure this; a
contumacious culprit may, however, be tortured until he performs the
act which is a prerequisite to his execution. Digital signatures are
sometimes required in the army to prevent personation; the general
in command at Wenchow enforces it on all his troops. A document thus
attested can no more be forged or repudiated than a photograph--not so
easily, for while the period of half a lifetime effects great changes
in the physiognomy, the rugae of the fingers present the same appearance
from the cradle to the grave; time writes no wrinkles there. In the
army everywhere, when the description of a person is written down, the
relative number of volutes and coniferous finger-tips is noted. It
is called taking the "whelk striae," the fusiform being called "rice
baskets," and the volutes "peck measures." A person unable to write, the
form of signature which defies personation or repudiation is required in
certain domestic cases, as in the sale of children or women. Often when
a child is sold the parents affix their finger marks to the bill of
sale; when a husband puts away his wife, giving her a bill of divorce,
he marks the document with his entire palm; and when a wife is sold, the
purchaser requires the seller to stamp the paper with hands and feet,
the four organs duly smeared with ink. Professional fortune tellers in
China take into account almost the entire system of the person whose
future they attempt to forecast, and of course they include palmistry,
but the rugae of the finger-ends do not receive much attention. Amateur
fortune-tellers, however, discourse as glibly on them as phrenologists
do of "bumps"--it is so easy. In children the relative number of volute
and conical striae indicate their future. "If there are nine volutes,"
says a proverb, "to one conical, the boy will attain distinction without
toil."
Regarded from an ethnological point of view, I can discover merely that
the rugae of Chinamen's fingers differ from Europeans', but there is so
little uniformity observable that they form no basis for distinction,
and while the striae may be noteworthy points in certain medico-legal
questions, heredity is not one of them.
* * * * *
LUCIDITY.
At the close of an interesting address lately delivered at the reopening
of the Liverpool University College and School of Medicine, Mr. Matthew
Arnold said if there was one word which he should like to plant in the
memories of his audience, and to leave sticking there after he had gone,
it was the word _lucidity_. If he had to fix upon the three great wants
at this moment of the three principal nations of Europe, he should say
that the great want of the French was morality, that the great want of
the Germans was civil courage, and that our own great want was lucidity.
Our own want was, of course, what concerned us the most. People were apt
to remark the defects which accompanied certain qualities, and to think
that the qualities could not be desirable because of the defects which
they saw accompanying them. There was no greater and salutary lesson for
men to learn than that a quality may be accompanied, naturally perhaps,
by grave dangers; that it may actually present itself accompanied by
terrible defects, and yet that it might itself be indispensable. Let him
illustrate what he meant by an example, the force of which they would
all readily feel. Seriousness was a quality of our nation. Perhaps
seriousness was always accompanied by certain dangers. But, at any rate,
many of our French neighbors would say that they found our seriousness
accompanied by so many false ideas, so much prejudice, so much that was
disagreeable, that it could not have the value which we attributed to
it. And yet we knew that it was invaluable. Let them follow the same
mode of reasoning as to the quality of lucidity. The French had a
national turn for lucidity as we had a national turn for seriousness.
Perhaps a national turn for lucidity carried with it always certain
dangers. Be this as it might, it was certain that we saw in the French,
along with their lucidity, a want of seriousness, a want of reverence,
and other faults, which greatly displeased us. Many of us were inclined
in consequence to undervalue their lucidity, or to deny that they
had it. We were wrong: it existed as our seriousness existed; it was
valuable as our seriousness was valuable. Both the one and the other
were valuable, and in the end indispensable.
What was lucidity? It was negatively that the French have it, and he
would therefore deal with its negative character merely. Negatively,
lucidity was the perception of the want of truth and validness in
notions long current, the perception that they are no longer possible,
that their time is finished, and they can serve us no more. All through
the last century a prodigious travail for lucidity was going forward
in France. Its principal agent was a man whose name excited generally
repulsion in England, Voltaire. Voltaire did a great deal of harm in
France. But it was not by his lucidity that he did harm; he did it by
his want of seriousness, his want of reverence, his want of sense for
much that is deepest in human nature. But by his lucidity he did good.
All admired Luther. Conduct was three-fourths of life, and a man who
worked for conduct, therefore, worked for more than a man who worked for
intelligence. But having promised this, it might be said that the Luther
of the eighteenth century and of the cultivated classes was Voltaire.
As Luther had an antipathy to what was immoral, so Voltaire had an
antipathy to what was absurd, and both of them made war upon the object
of their antipathy with such masterly power, with so much conviction,
so much energy, so much genius, that they carried their world with
them--Luther his Protestant world, and Voltaire his French world--and
the cultivated classes throughout the continent of Europe generally.
Voltaire had more than negative lucidity; he had the large and true
conception that a number and equilibrium of activities were necessary
for man. "_Il faut douner a notre ame toutes les formes possibles_"
was a maxim which Voltaire really and truly applied in practice,
"advancing," as Michelet finely said of him, in every direction with
a marvelous vigor and with that conquering ambition which Vico called
_mens heroica_. Nevertheless. Voltaire's signal characteristic was his
lucidity, his negative lucidity.
There was a great and free intellectual movement in England in the
eighteenth century--indeed, it was from England that it passed into
France; but the English had not that strong natural bent for lucidity
which the French had. Its bent was toward other things in preference.
Our leading thinkers had not the genius and passion for lucidity which
distinguished Voltaire. In their free inquiry they soon found themselves
coming into collision with a number of established facts, beliefs,
conventions. Thereupon all sorts of practical considerations began to
sway them. The danger signal went up, they often stopped short, turned
their eyes another way, or drew down a curtain between themselves and
the light. "It seems highly probable," said Voltaire, "that nature has
made thinking a portion of the brain, as vegetation is a function of
trees; that we think by the brain just as we walk by the feet." So our
reason, at least, would lead us to conclude, if the theologians did not
assure us of the contrary; such, too, was the opinion of Locke, but he
did not venture to announce it. The French Revolution came, England grew
to abhor France, and was cut off from the Continent, did great things,
gained much, but not in lucidity. The Continent was reopened, the
century advanced, time and experience brought their lessons, lovers of
free and clear thought, such as the late John Stuart Mill, arose among
us. But we could not say that they had by any means founded among us the
reign of lucidity.
Let them consider that movement of which we were hearing so much just
now: let them look at the Salvation Army and its operations. They would
see numbers, funds, energy, devotedness, excitement, conversions, and
a total absence of lucidity. A little lucidity would make the whole
movement impossible. That movement took for granted as its basis what
was no longer possible or receivable; its adherents proceeded in all
they did on the assumption that that basis was perfectly solid, and
neither saw that it was not solid, nor ever even thought of asking
themselves whether it was solid or not.
Taking a very different movement, and one of far higher dignity and
import, they had all had before their minds lately the long-devoted,
laborious, influential, pure, pathetic life of Dr. Pusey, which had just
ended. Many of them had also been reading in the lively volumes of that
acute, but not always good-natured rattle, Mr. Mozley, an account of
that great movement which took from Dr. Pusey its earlier name. Of its
later stage of Ritualism they had had in this country a now celebrated
experience. This movement was full of interest. It had produced men to
be respected, men to be admired, men to be beloved, men of learning,
goodness, genius, and charm. But could they resist the truth that
lucidity would have been fatal to it? The movers of all those questions
about apostolical succession, church patristic authority, primitive
usage, postures, vestments--questions so passionately debated, and on
which he would not seek to cast ridicule--did not they all begin by
taking for granted something no longer possible or receivable, build on
this basis as if it were indubitably solid, and fail to see that their
basis not being solid, all they built upon it was fantastic?
He would not say that negative lucidity was in itself a satisfactory
possession, but he said that it was inevitable and indispensable, and
that it was the condition of all serious construction for the future.
Without it at present a man or a nation was intellectually and
spiritually all abroad. If they saw it accompanied in France by much
that they shrank from, they should reflect that in England it would
have influences joined with it which it had not in France--the natural
seriousness of the people, their sense of reverence and respect, their
love for the past. Come it must; and here where it had been so late in
coming, it would probably be for the first time seen to come without
danger.
Capitals were natural centers of mental movement, and it was natural for
the classes with most leisure, most freedom, most means of cultivation,
and most conversance with the wide world to have lucidity though often
they had it not. To generate a spirit of lucidity in provincial towns,
and among the middle classes bound to a life of much routine and plunged
in business, was more difficult. Schools and universities, with serious
and disinterested studies, and connecting those studies the one with the
other and continuing them into years of manhood, were in this case the
best agency they could use. It might be slow, but it was sure. Such
an agency they were now going to employ. Might it fulfill all their
expectations! Might their students, in the words quoted just now,
advance in every direction with a marvelous vigor, and with that
conquering ambition which Vico called _mens heroica_! And among the many
good results of this, might one result be the acquisition in their midst
of that indispensable spirit--the spirit of lucidity!
* * * * *
ON SOME APPARATUS THAT PERMIT OF ENTERING FLAMES.
[Footnote: A. de Rochas in the _Revue Scientifique_.]
In the following notes I shall recall a few experiments that indicate
under what conditions the human organism is permitted to remain unharmed
amid flames. These experiments were published in England in 1882, in the
twelfth letter from Brewster to Walter Scott on natural magic. They are,
I believe, not much known in France, and possess a practical interest
for those who are engaged in the art of combating fires.
At the end of the last century Humphry Davy observed that, on placing a
very fine wire gauze over a flame, the latter was cooled to such a
point that it could not traverse the meshes. This phenomenon, which he
attributed to the conductivity and radiating power of the metal, he soon
utilized in the construction of a lamp for miners.
Some years afterward Chevalier Aldini, of Milan, conceived the idea of
making a new application of Davy's discovery in the manufacture of an
envelope that should permit a man to enter into the midst of flames.
This envelope, which was made of metallic gauze with 1-25th of an inch
meshes, was composed of five pieces, as follows: (1) a helmet, with
mask, large enough, to allow a certain space between it and the internal
bonnet of which I shall speak; (2) a cuirass with armlets; (3) a skirt
for the lower part of the belly and the thighs; (4) a pair of boots
formed of a double wire gauze; and (5) a shield five feet long by one
and a half wide, formed of metallic gauze stretched over a light iron
frame. Beneath this armor the experimenter was clad in breeches and a
close coat of coarse cloth that had previously been soaked in a solution
of alum. The head, hands, and feet were covered by envelopes of asbestos
cloth whose fibers were about a half millimeter in diameter. The bonnet
contained apertures for the eyes, nose, and ears, and consisted of a
single thickness of fabric, as did the stockings, but the gloves were of
double thickness, so that the wearer could seize burning objects with
the hands.
Aldini, convinced of the services that his apparatus might render to
humanity, traveled over Europe and gave gratuitous representations with
it. The exercises generally took place in the following order: Aldini
began by first wrapping his finger in asbestos and then with a double
layer of wire gauze. He then held it for some instants in the flame of
a candle or alcohol lamp. One of his assistants afterward put on the
asbestos glove of which I have spoken, and, protecting the palm of his
hand with another piece of asbestos cloth, seized a piece of red-hot
iron from a furnace and slowly carried it to a distance of forty or
fifty meters, lighted some straw with it, and then carried it back to
the furnace. On other occasions, the experimenters, holding firebrands
in their hands, walked for five minutes over a large grating under which
fagots were burning.
In order to show how the head, eyes, and lungs were protected by the
wire gauze apparatus, one of the experimenters put on the asbestos
bonnet, helmet, and cuirass, and fixed the shield in front of his
breast. Then, in a chafing dish placed on a level with his shoulder, a
great fire of shavings was lighted, and care was taken to keep it up.
Into the midst of these flames the experimenter then plunged his head
and remained thus five or six minutes with his face turned toward them.
In an exhibition given at Paris before a committee from the Academic
des Sciences, there were set up two parallel fences formed of straw,
connected by iron wire to light wicker work, and arranged so as to leave
between them a passage 3 feet wide by 30 long. The heat was so intense,
when the fences were set on fire, that no one could approach nearer than
20 or 25 feet; and the flames seemed to fill the whole space between
them, and rose to a height of 9 or 10 feet. Six men clad in the Aldini
suit went in, one behind the other, between the blazing fences, and
walked slowly backward and forward in the narrow passage, while the fire
was being fed with fresh combustibles from the exterior. One of these
men carried on his back, in an ozier basket covered with wire gauze, a
child eight years of age, who had on no other clothing than an asbestos
bonnet. This same man, having the child with him, entered on another
occasion a clear fire whose flames reached a height of 18 feet, and
whose intensity was such that it could not be looked at. He remained
therein so long that the spectators began to fear that he had succumbed;
but he finally came out safe and sound.
One of the conclusions to be drawn from the facts just stated is that
man can breathe in the midst of flames. This marvelous property cannot
be attributed exclusively to the cooling of the air by its passage
through the gauze before reaching the lungs; it shows also a very great
resistance of our organs to the action of heat. The following, moreover,
are direct proofs of such resistance. In England, in their first
experiment, Messrs. Joseph Banks, Charles Blagden, and Dr. Solander
remained for ten minutes in a hot-house whose temperature was 211 deg.
Fahr., and their bodies preserved therein very nearly the usual heat. On
breathing against a thermometer they caused the mercury to fall several
degrees. Each expiration, especially when it was somewhat strong,
produced in their nostrils an agreeable impression of coolness, and the
same impression was also produced on their fingers when breathed upon.
When they touched themselves their skin seemed to be as cold as that of
a corpse; but contact with their watch chains caused them to experience
a sensation like that of a burn. A thermometer placed under the tongue
of one of the experimenters marked 98 deg. Fahr., which is the normal
temperature of the human species.
Emboldened by these first results, Blagden entered a hot-house in which
the thermometer in certain parts reached 262 deg. Fahr. He remained therein
eight minutes, walked about in all directions, and stopped in the
coolest part, which was at 240 deg. Fahr. During all this time he
experienced no painful sensations; but, at the end of seven minutes, he
felt an oppression of the lungs that inquieted him and caused him to
leave the place. His pulse at that moment showed 144 beats to the
minute, that is to say, double what it usually did. To ascertain whether
there was any error in the indications of the thermometer, and to find
out what effect would take place on inert substances exposed to the hot
air that he had breathed, Blogden placed some eggs in a zinc plate in
the hot-house, alongside the thermometer, and found that in twenty
minutes they were baked hard.
A case is reported where workmen entered a furnace for drying moulds, in
England, the temperature of which was 177 deg., and whose iron sole plate
was so hot that it carbonized their wooden shoes. In the immediate
vicinity of this furnace the temperature rose to 160 deg.. Persons not of
the trade who approached anywhere near the furnace experienced pain in
the eyes, nose, and ears.
A baker is cited in Angoumois, France, who spent ten minutes in a
furnace at 132 deg. C.
The resistance of the human organism to so high temperatures can be
attributed to several causes. First, it has been found that the quantity
of carbonic acid exhaled by the lungs, and consequently the chemical
phenomena of internal combustion that are a source of animal heat,
diminish in measure as the external temperature rises. Hence, a conflict
which has for result the retardation of the moment at which a living
being will tend, without obstacle, to take the temperature of the
surrounding medium. On another hand, it has been observed that man
resists heat so much the less in proportion as the air is saturated
with vapors. Dr. Berger, who supported for seven minutes a temperature
varying from 109 deg. to 110 deg. C. in dry air, could remain only twelve
minutes in a bagnio whose temperature rose from 41 deg. to 51.75 deg.. At the
Hammam of Paris the highest temperature obtained is 87 deg., and Dr. E.
Martin has not been able to remain therein more than five minutes. This
physician reports that in 1743, the thermometer having exceeded 40 deg. at
Pekin, 14,000 persons perished. These facts are explained by the cooling
that the evaporation of perspiration produces on the surface of the
body. Edwards has calculated that such evaporation is ten times greater
in dry air in motion than in calm and humid air. The observations become
still more striking when the skin is put in contact with a liquid or a
solid which suppresses perspiration. Lemoine endured a bath of Bareges
water of 37 deg. for half an hour; but at 45 deg. he could not remain in it more
than seven minutes, and the perspiration began to flow at the end of six
minutes. According to Brewster, persons who experience no malaise near
a fire which communicates a temperature of 100 deg. C. to them, can hardly
bear contact with alcohol and oil at 55 deg. and mercury at 48 deg..
The facts adduced permit us to understand how it was possible to bear
one of the proofs to which it is said those were submitted who wished
to be initiated into the Egyptian mysteries. In a vast vaulted chamber
nearly a hundred feet long, there were erected two fences formed of
posts, around which were wound branches of Arabian balm, Egyptian thorn,
and tamarind--all very flexible and inflammable woods. When this was set
on fire the flames arose as far as the vault, licked it, and gave the
chamber the appearance of a hot furnace, the smoke escaping through
pipes made for the purpose. Then the door was suddenly opened before the
neophyte, and he was ordered to traverse this burning place, whose floor
was composed of an incandescent grating.
The Abbe Terrason recounts all these details in his historic romance
"Sethos," printed at the end of last century. Unfortunately literary
frauds were in fashion then, and the book, published as a translation of
an old Greek manuscript, gives no indication of sources. I have sought
in special works for the data which the abbe must have had as a basis,
but I have not been able to find them. I suppose, however, that
this description, which is so precise, is not merely a work of the
imagination. The author goes so far as to give the dimensions of the
grating (30 feet by 8), and, greatly embarrassed to explain how his hero
was enabled to traverse it without being burned, is obliged to suppose
it to have been formed of very thick bars, between which Sethos had care
to place his feet. But this explanation is inadmissible. He who had the
courage to rush, head bowed, into the midst of the flames, certainly
would not have amused himself by choosing the place to put his feet.
Braving the fire that surrounded his entire body, he must have had no
other thought than that of reaching the end of his dangerous voyage as
soon as possible. We cannot see very well, moreover, how this immense
grate, lying on the ground, was raised to a red heat and kept at such a
temperature. It is infinitely more simple to suppose that between the
two fences there was a ditch sufficiently deep in which a fire had
also been lighted, and which was covered by a grating as in the Aldini
experiments. It is even probable that this grating was of copper,
which, illuminated by the fireplace, must have presented a terrifying
brilliancy, while in reality it served only to prevent the flames from
the fireplace reaching him who dared to brave them.
* * * * *
THE BUILDING STONE SUPPLY.
The use of stone as a building material was not resorted to, except to
a trifling extent, in this country until long after the need of such a
solid substance was felt. The early settler contented himself with the
log cabin, the corduroy road, and the wooden bridge, and loose stone
enough for foundation purposes could readily be gathered from the
surface of the earth. Even after the desirability of more handsome and
durable building material for public edifices in the colonial cities
than wood became apparent, the ample resources which nature had afforded
in this country were overlooked, and brick and stone were imported by
the Dutch and English settlers from the Old World. Thus we find the
colonists of the New Netherlands putting yellow brick on their list
of non-dutiable imports in 1648; and such buildings in Boston as are
described as being "fairly set forth with brick, tile, slate, and
stone," were thus provided only with foreign products. Isolated
instances of quarrying stone are known to have occurred in the last
century; but they are rare. The edifice known as "King's Chapel,"
Boston, erected in 1752, is the first one on record as being built from
American stone; this was granite, brought from Braintree, Mass.
Granite is a rock particularly abundant in New England, though also
found in lesser quantities elsewhere in this country. The first granite
quarries that were extensively developed were those at Quincy, Mass.,
and work began at that point early in the present century. The fame of
the stone became widespread, and it was sent to distant markets--even to
New Orleans. The old Merchants' Exchange in New York (afterward used as
a custom house) the Astor House in that city, and the Custom House in
New Orleans, all nearly or quite fifty years old, were constructed of
Quincy granite, as were many other fine buildings along the Atlantic
coast. In later years, not only isolated public edifices, but also whole
blocks of stores, have been constructed of this material. It was from
the Quincy quarries that the first railroad in this country was built;
this was a horse-railroad, three miles long, extending to Neponset
River, built in 1827.
Other points in Massachusetts have been famed for their excellent
granite. After Maine was set off as a distinct State, Fox Island
acquired repute for its granite, and built up an extensive traffic
therein. Westerly, R.I., has also been engaged in quarrying this
valuable rock for many years, most of its choicer specimens having been
wrought for monumental purposes. Statues and other elaborate monumental
designs are now extensively made therefrom. Smaller pieces and a coarser
quality of the stone are here and elsewhere along the coast obtained in
large quantities for the construction of massive breakwaters to protect
harbors. Another point famous for its granite is Staten Island, New
York. This stone weighs 180 pounds to the cubic foot, while the Quincy
granite weighs but 165. The Staten Island product is used not only for
building purposes, but is also especially esteemed for paving after both
the Russ and Belgian patents. New York and other cities derive large
supplies from this source. The granite of Weehawken, N.J., is of the
same character, and greatly in demand. Port Deposit, Md., and Richmond,
Va, are also centers of granite production. Near Abbeville, S.C., and
in Georgia, granite is found quite like that of Quincy. Much southern
granite, however, decomposes readily, and is almost as soft as clay.
This variety of stone is found in great abundance in the Rocky
Mountains; but, except to a slight extent in California, it is not yet
quarried there.
Granite, having little grain, can be cut into blocks of almost any size
and shape. Specimens as much as eighty feet long have been taken out and
transported great distances. The quarrying is done by drilling a series
of small holes, six inches or more deep and almost the same distance
apart, inserting steel wedges along the whole line and then tapping each
gently with a hammer in succession, in order that the strain may be
evenly distributed.
A building material that came into use earlier than granite is known as
freestone or sandstone; although its first employment does not date back
further than the erection of King's Chapel, Boston, already referred to
as the earliest well-known occasion where granite was used in building.
Altogether the most famous American sandstone quarries are those at
Portland, on the Connecticut River, opposite Middletown. These were
worked before the Revolution; and their product has been shipped to many
distant points in the country. The long rows of "brownstone fronts" in
New York city are mostly of Portland stone, though in many cases the
walls are chiefly of brick covered with thin layers of the stone. The
old red sandstone of the Connecticut valley is distinguished in geology
for the discovery of gigantic fossil footprints of birds, first noticed
in the Portland quarries in 1802. Some of these footprints measured
ten to sixteen inches, and they were from four to six feet apart. The
sandstone of Belleville, N.J., has also extensive use and reputation.
Trinity Church in New York city and the Boston Atheneum are built of the
product of these quarries; St. Lawrence County, New York, is noted also
for a fine bed of sandstone. At Potsdam it is exposed to a depth of
seventy feet. There are places though, in New England, New York, and
Eastern Pennsylvania, where a depth of three hundred feet has been
reached. The Potsdam sandstone is often split to the thinness of an
inch. It hardens by exposure, and is often used for smelting furnace
hearth-stones. Shawangunk Mountain, in Ulster County, yields a sandstone
of inferior quality, which has been unsuccessfully tried for paving;
as it wears very unevenly. From Ulster, Greene, and Albany Counties
sandstone slabs for sidewalks are extensively quarried for city use;
the principal outlets of these sections being Kingston, Saugerties,
Coxsackie, Bristol, and New Baltimore, on the Hudson. In this region
quantities amounting to millions of square feet are taken out in large
sheets, which are often sawed into the sizes desired. The vicinity of
Medina, in Western New York, yields a sandstone extensively used in that
section for paving and curbing, and a little for building. A rather poor
quality of this stone has been found along the Potomac, and some of it
was used in the erection of the old Capitol building at Washington.
Ohio yields a sandstone that is of a light gray color; Berea, Amherst,
Vermilion, and Massillon are the chief points of production. St.
Genevieve, Mo., yields a stone of fine grain of a light straw color,
which is quite equal to the famous Caen stone of France. The Lake
Superior sandstones are dark and coarse grained, but strong.
In some parts of the country, where neither granite nor sandstone
is easily procured, blue and gray limestone are sometimes used for
building, and, when hammer dressed, often look like granite. A serious
objection to their use, however, is the occasional presence of iron,
which rusts on exposure, and defaces the building. In Western New York
they are widely used. Topeka stone, like the coquine of Florida and
Bermuda, is soft like wood when first quarried, and easily wrought,
but it hardens on exposure. The limestones of Canton, Mo., Joliet and
Athens, Ill., Dayton, Sandusky, Marblehead, and other points in Ohio,
Ellittsville, Ind., and Louisville and Bowling Green, Ky., are great
favorites west. In many of these regions limestone is extensively used
for macadamizing roads, for which it is excellently adapted. It also
yields excellent slabs or flags for sidewalks.
One of the principal uses of this variety of stone is its conversion, by
burning, into lime for building purposes. All limestones are by no
means equally excellent in this regard. Thomaston lime, burned with
Pennsylvania coal, near the Penobscot River, has had a wide reputation
for nearly half a century. It has been shipped thence to all points
along the Atlantic coast, invading Virginia as far as Lynchburg, and
going even to New Orleans, Smithfield, R.I., and Westchester County,
N.Y., near the lower end of the Highlands, also make a particularly
excellent quality of lime. Kingston, in Ulster County, makes an inferior
sort for agricultural purposes. The Ohio and other western stones yield
a poor lime, and that section is almost entirely dependent on the east
for supplies.
Marbles, like limestones, with which they are closely related, are very
abundant in this country, and are also to be found in a great variety of
colors. As early as 1804 American marble was used for statuary purposes.
Early in the century it also obtained extensive employment for
gravestones. Its use for building purposes has been more recent than
granite and sandstone in this country; and it is coming to supersede the
latter to a great degree. For mantels, fire-places, porch pillars, and
like ornamental purposes, however, our variegated, rich colored and
veined or brecciated marbles were in use some time before exterior walls
were made from them. Among the earliest marble buildings were Girard
College in Philadelphia and the old City Hall in New York, and the
Custom House in the latter city, afterward used for a sub-treasury. The
new Capitol building at Washington is among the more recent structures
composed of this material. Our exports of marble to Cuba and elsewhere
amount to over $300,000 annually, although we import nearly the same
amount from Italy. And yet an article can be found in the United States
fully as fine as the famous Carrara marble. We refer to that which comes
from Rutland, Vt. This state yields the largest variety and choicest
specimens. The marble belt runs both ways from Rutland County, where
the only quality fit for statuary is obtained. Toward the north it
deteriorates by growing less sound, though finer in grain; while to
the south it becomes coarser. A beautiful black marble is obtained at
Shoreham, Vt. There are also handsome brecciated marbles in the same
state; and in the extreme northern part, near Lake Champlain, they
become more variegated and rich in hue. Such other marble as is found
in New England is of an inferior quality. The pillars of Girard
College came from Berkshire, Mass., which ranks next after Vermont in
reputation.
The marble belt extends from New England through New York, Pennsylvania,
Maryland, the District of Columbia, and Virginia, Tennessee, and the
Carolinas, to Georgia and Alabama. Some of the variegated and high
colored varieties obtained near Knoxville, Tenn., nearly equal that of
Vermont. The Rocky Mountains contain a vast abundance and variety.
Slate was known to exist in this country to a slight extent in colonial
days. It was then used for gravestones, and to some extent for roofing
and school purposes. But most of our supplies came from Wales. It is
stated that a slate quarry was operated in Northampton County, Pa., as
early as 1805. In 1826 James M. Porter and Samuel Taylor engaged in the
business, obtaining their supplies from the Kittanninny Mountains. From
this time the business developed rapidly, the village of Slateford being
an outgrowth of it, and large rafts being employed to float the product
down the Schuylkill to Philadelphia. By 1860 the industry had reached
the capacity of 20,000 cases of slate, valued at $10 a case, annually.
In 1839 quarries were opened in the Piscataquis River, forty miles
north of Bangor, Me., but poor transportation facilities retarded the
business. Vermont began to yield in 1852. New York's quarries are
confined to Washington County, near the Vermont line. Maryland has
a limited supply from Harford County. The Huron Mountains, north of
Marquette, Mich., contain slate, which is also said to exist in Pike
County, Ga.
Grindstones, millstones, and whetstones are quarried in New York, Ohio,
Michigan, Pennsylvania, and other States. Mica is found at Acworth and
Grafton, N. H., and near Salt Lake, but our chief supply comes from
Haywood, Yancey, Mitchell, and Macon counties, in North Carolina, and
our product is so large that we can afford to export it. Other stones,
such as silex, for making glass, etc., are found in profusion in various
parts of the country, but we have no space to enter into a detailed
account of them at present.--_Pottery and Glassware Reporter_.
* * * * *
AN INDUSTRIAL REVOLUTION.
The most interesting change of which the Census gives account is the
increase in the number of farms. The number has virtually doubled within
twenty years. The population of the country has not increased in like
proportion. A large part of the increase in number of farms has been due
to the division of great estates. Nor has this occurred, as some may
imagine, exclusively in the Southern States and the States to which
immigration and migration have recently been directed. It is an
important fact that the multiplication of farms has continued even in
the older Northern States, though the change has not been as great in
these as in States of the far West or the South. In New York there has
been an increase of 25,000, or 11.5 per cent, in the number of farms
since 1870; in New Jersey the increase has been 12.2 per cent., and in
Pennsylvania 22.7 per cent., though the increase in population, and
doubtless in the number of persons engaged in farming, has been much
smaller. Ohio, Indiana, and Illinois also, have been considered fully
settled States for years, at least in an agricultural point of view, and
yet the number of farms has increased 26.1 per cent, in ten years in
Ohio, 20.3 percent, in Indiana, and 26.1 per cent, in Illinois. The
obvious explanation is that the growth of many cities and towns has
created a market for a far greater supply of those products which may be
most advantageously grown upon farms of moderate size; but even if this
fully accounts for the phenomenon, the change must be recognized as one
of the highest importance industrially, socially, and politically. The
man who owns or rents and cultivates a farm stands on a very different
footing from the laborer who works for wages. It is not a small matter
that, in these six States alone, there are 205,000 more owners or
managers of farms than there were only a decade ago.
As we go further toward the border, west or north, the influence of the
settlement of new land is more distinctly felt. Even in Michigan, where
new railroads have opened new regions to settlement, the increase in
number of farms has been over 55 per cent. In Wisconsin, though the
increase in railroad mileage has been about the same as in Michigan, the
reported increase in number of farms has been only 28 per cent., but in
Iowa it rises to 60 per cent., and in Minnesota to nearly 100 per cent.
In Kansas the number of farms is 138,561, against 38,202 in 1870; in
Nebraska 63,387, against 12,301; and in Dakota 17,435, against 1,720. In
these regions the process is one of creation of new States rather than a
change in the social and industrial condition of the population.
Some Southern States have gained largely, but the increase in these,
though very great, is less surprising than the new States of the
Northwest. The prevailing tendency of Southern agriculture to large
farms and the employment of many hands is especially felt in States
where land is still abundant. The greatest increase is in Texas, where
174,184 farms are reported, against 61,125 in 1870; in Florida, with
23,438 farms, against 10,241 in 1870; and in Arkansas, with 94,433
farms, against 49,424 in 1870. In Missouri 215,575 farms are reported,
against 148,228 in 1870. In these States, though social changes have
been great, the increase in number of farms has been largely due to new
settlements, as in the States of the far Northwest. But the change in
the older Southern States is of a different character.
Virginia, for example, has long been settled, and had 77,000 farms
thirty years ago. But the increase in number within the past ten years
has been 44,668, or 60.5 per cent. Contrasting this with the increase in
New York, a remarkable difference appears. West Virginia had few more
farms ten years ago than New Jersey; now it has nearly twice as many,
and has gained in number nearly 60 per cent. North Carolina, too, has
increased 78 per cent. in number of farms since 1870, and South Carolina
80 per cent. In Georgia the increase has been still greater--from 69,956
to 138,626, or nearly 100 per cent. In Alabama there are 135,864
farms, against 67,382 in 1870, an increase of over 100 per cent. These
proportions, contrasted with those for the older Northern States, reveal
a change that is nothing less than an industrial revolution. But the
force of this tendency to division of estates has been greatest in the
States named. Whereas the ratio of increase in number of farms becomes
greater in Northern States as we go from the East toward the Mississippi
River, at the South it is much smaller in Kentucky, Tennessee,
Mississippi, and Louisiana than in the older States on the Atlantic
coast. Thus in Louisiana the increase has been from 28,481 to 48,292
farms, or 70 per cent., and in Mississippi from 68,023 to 101,772 farms,
or less than 50 per cent., against 100 in Alabama and Georgia. In
Kentucky the increase has been from 118,422 to 166,453 farms, or 40 per
cent., and in Tennessee from 118,141 to 165,650 farms, or 40 per cent.,
against 60 in Virginia and West Virginia, and 78 in North Carolina.
Thus, while the tendency to division is far greater than in the Northern
States of corresponding age, it is found in full force only in six of
the older Southern States, Alabama, West Virginia, and four on the
Atlantic coast. In these, the revolution already effected foreshadows
and will almost certainly bring about important political changes within
a few years. In these six States there 310,795 more farm owners or
occupants than there were ten years ago.--_N.Y. Tribune_.
* * * * *
A FARMER'S LIME KILN.
For information about burning lime we republish the following article
furnished by a correspondent of the _Country Gentleman_ several years
ago:
[Illustration: Fig. 1. Fig. 2. Fig. 3. A (Fig. 1), Railway Track--B B B,
Iron Rods running through Kiln--C, Capstone over Arch--D, Arch--E, Well
without brick or ash lining.]
I send you a description and sketch of a lime-kiln put up on my premises
about five years ago. The dimensions of this kiln are 13 feet square by
25 feet high from foundation, and its capacity 100 bushels in 24 hours.
It was constructed of the limestone quarried on the spot. It has round
iron rods (shown in sketch) passing through, with iron plates fastened
to the ends as clamps to make it more firm; the pair nearest the top
should be not less than 2 feet from that point, the others interspersed
about 2 feet apart--the greatest strain being near the top. The arch
should be 7 feet high by 51/2 wide in front, with a gather on the top
and sides of about 1 foot, with plank floor; and if this has a little
incline it will facilitate shoveling the lime when drawn. The arch
should have a strong capstone; also one immediately under the well of
the kiln, with a hole 2 feet in diameter to draw the lime through; or
two may be used with semicircle cut in each. Iron bars 2 inches wide by
1/8 inch thick are used in this kiln for closing it, working in slots
fastened to capstone. These slots must be put in before the caps
are laid. When it is desired to draw lime, these bars may be
pushed laterally in the slots, or drawn out entirely, according to
circumstances; 3 bars will be enough. The slots are made of iron bars
11/2 inches wide, with ends rounded and turned up, and inserted in holes
drilled through capstone and keyed above.
The well of the kiln is lined with fire-brick one course thick, with a
stratum of coal ashes three inches thick tamped in between the brick
and wall, which proves a great protection to the wall. About 2,000
fire-bricks were used. The proprietors of this kiln say about one-half
the lower part of the well might have been lined with a first quality of
common brick and saved some expense and been just as good. The form of
the well shown in Fig. 3 is 7 feet in diameter in the bilge, exclusive
of the lining of brick and ashes. Experiments in this vicinity have
proved this to be the best, this contraction toward the top being
absolutely necessary, the expansion of the stone by the heat is so
great that the lime cannot be drawn from perpendicular walls, as was
demonstrated in one instance near here, where a kiln was built on that
principle. The kiln, of course, is for coal, and our stone requires
about three-quarters of a ton per 100 bushels of lime, but this, I am
told, varies according to quality, some requiring more than others; the
quantity can best be determined by experimenting; also the regulation of
the heat--if too great it will cause the stones to melt or run together
as it were, or, if too little, they will not be properly burned. The
business requires skill and judgment to run it successfully.
This kiln is located at the foot of a steep bluff, the top about level
with the top of the kiln, with railway track built of wooden sleepers,
with light iron bars, running from the bluff to the top of the kiln, and
a hand-car makes it very convenient filling the kiln. Such a location
should be had if possible. Your inquirer may perhaps get some ideas
of the principles of a kiln for using _coal_. The dimensions may be
reduced, if desired. If for _wood_, the arch would have to be formed for
that, and the height of kiln reduced.
* * * * *
THE MANUFACTURE OF APPLE JELLY.
[Footnote: From the report of the New York Agricultural Society.]
Within the county of Oswego, New York, Dewitt C. Peck reports there are
five apple jelly factories in operation. The failure of the apple crop,
for some singular and unexplained reason, does not extend in great
degree to the natural or ungrafted fruit. Though not so many as common,
even of these apples, there are yet enough to keep these five mills and
the numerous cider mills pretty well employed. The largest jelly factory
is located near the village of Mexico, and as there are some features in
regard to this manufacture peculiar to this establishment which may be
new and interesting, we will undertake a brief description. The factory
is located on the Salmon Creek, which affords the necessary power. A
portion of the main floor, first story, is occupied as a saw mill,
the slabs furnishing fuel for the boiler furnace connected with the
evaporating department. Just above the mill, along the bank of the pond,
and with one end projecting over the water, are arranged eight large
bins, holding from five hundred to one thousand bushels each, into which
the apples are delivered from the teams. The floor in each of these has
a sharp pitch or inclination toward the water and at the lower end is a
grate through which the fruit is discharged, when wanted, into a trough
half submerged in the pond.
The preparation of the fruit and extraction of the juice proceeds
as follows: Upon hoisting a gate in the lower end of this trough,
considerable current is caused, and the water carries the fruit a
distance of from thirty to one hundred feet, and passes into the
basement of the mill, where, tumbling down a four-foot perpendicular
fall, into a tank, tight in its lower half and slatted so as to permit
the escape of water and impurities in the upper half, the apples are
thoroughly cleansed from all earthy or extraneous matter. Such is the
friction caused by the concussion of the fall, the rolling and rubbing
of the apples together, and the pouring of the water, that decayed
sections of the fruit are ground off and the rotten pulp passes away
with other impurities. From this tank the apples are hoisted upon an
endless chain elevator, with buckets in the form of a rake-head with
iron teeth, permitting drainage and escape of water, to an upper story
of the mill, whence by gravity they descend to the grater. The press
is wholly of iron, all its motions, even to the turning of the screws,
being actuated by the water power. The cheese is built up with layers
inclosed in strong cotton cloth, which displaces the straw used in olden
time, and serves also to strain the cider. As it is expressed from
the press tank, the cider passes to a storage tank, and thence to the
defecator.
This defecator is a copper pan, eleven feet long and about three feet
wide. At each end of this pan is placed a copper tube three inches in
diameter and closed at both ends. Lying between and connecting
these two, are twelve tubes, also of copper, 11/2 inches in diameter,
penetrating the larger tubes at equal distances from their upper and
under surfaces, the smaller being parallel with each other, and 11/2
inches apart. When placed in position, the larger tubes, which act as
manifolds, supplying the smaller with steam, rest upon the bottom of the
pan, and thus the smaller pipes have a space of three-fourths of an inch
underneath their outer surfaces.
The cider comes from the storage tank in a continuous stream about
three-eighths of an inch in diameter. Steam is introduced to the large
or manifold tubes, and from them distributed through the smaller ones at
a pressure of from twenty-five to thirty pounds per inch. Trap valves
are provided for the escape of water formed by condensation within the
pipes. The primary object of the defecator is to remove all impurities
and perfectly clarify the liquid passing through it. All portions of
pomace and other minute particles of foreign matter, when heated,
expand and float in the form of scum upon the surface of the cider. An
ingeniously contrived floating rake drags off this scum and delivers it
over the side of the pan. To facilitate this removal, one side of the
pan, commencing at a point just below the surface of the cider, is
curved gently outward and upward, terminating in a slightly inclined
plane, over the edge of which the scum is pushed by the rake into a
trough and carried away. A secondary purpose served by the defecator
is that of reducing the cider by evaporation to a partial sirup of the
specific gravity of about 20 deg. Baume. When of this consistency the liquid
is drawn from the bottom and less agitated portion of the defecator by a
siphon, and thence carried to the evaporator, which is located upon the
same framework and just below the defecator.
The evaporator consists of a separate system of six copper tubes, each
twelve feet long and three inches in diameter. These are each jacketed
or inclosed in an iron pipe of four inches internal diameter, fitted
with steam-tight collars so as to leave half an inch steam space
surrounding the copper tubes. The latter are open at both ends
permitting the admission and egress of the sirup and the escape of the
steam caused by evaporation therefrom, and are arranged upon the frame
so as to have a very slight inclination downward in the direction of
the current, and each nearly underneath its predecessor in regular
succession. Each is connected by an iron supply pipe, having a steam
gauge or indicator attached, with a large manifold, and that by other
pipes with a steam boiler of thirty horse power capacity. Steam being
let on at from twenty five to thirty pounds pressure, the stream of
sirup is received from the defecator through a strainer, which removes
any impurities possibly remaining into the upper evaporator tube;
passing in a gentle flow through that, it is delivered into a funnel
connected with the next tube below, and so, back and forth, through the
whole system. The sirup enters the evaporator at a consistency of from
20 deg. to 23 deg. Baume, and emerges from the last tube some three minutes
later at a consistency of from 30 deg. to 32 deg. Baume, which is found on
cooling to be the proper point for perfect jelly. This point is found to
vary one or two degrees, according to the fermentation consequent upon
bruises in handling the fruit, decay of the same, or any little delay in
expressing the juice from the cheese. The least fermentation occasions
the necessity for a lower reduction. To guard against this, no cheese
is allowed to stand over night, no pomace left in the grater or vat, no
cider in the tank; and further to provide against fermentation, a large
water tank is located upon the roof and filled by a force pump, and by
means of hose connected with this, each grater, press, vat, tank, pipe,
trough, or other article of machinery used, can be thoroughly washed and
cleansed. Hot water, instead of cider, is sometimes sent through the
defecator, evaporator, etc., until all are thoroughly scalded and
purified. If the saccharometer shows too great or too little reduction,
the matter is easily regulated by varying the steam pressure in the
evaporator by means of a valve in the supply pipe. If boiled cider
instead of jelly is wanted for making pies, sauces, etc., it is drawn
off from one of the upper evaporator tubes according to the consistency
desired; or can be produced at the end of the process by simply reducing
the steam pressure.
As the jelly emerges from the evaporator it is transferred to a tub
holding some fifty gallons, and by mixing a little therein, any little
variations in reduction or in the sweetness or sourness of the fruit
used are equalized. From this it is drawn through faucets, while hot,
into the various packages in which it is shipped to market. A favorite
form of package for family use is a nicely turned little wooden
bucket with cover and bail, two sizes, holding five and ten pounds
respectively. The smaller packages are shipped in cases for convenience
in handling. The present product of this manufactory is from 1,500 to
1,800 pounds of jelly each day of ten hours. It is calculated that
improvements now in progress will increase this to something more than a
ton per day. Each bushel of fruit will produce from four to five pounds
of jelly, fruit ripening late in the season being more productive than
earlier varieties. Crab apples produce the finest jelly; sour, crabbed,
natural fruit makes the best looking article, and a mixture of all
varieties gives most satisfactory results as to flavor and general
quality.
As the pomace is shoveled from the finished cheese, it is again ground
under a toothed cylinder, and thence drops into large troughs, through a
succession of which a considerable stream of water is flowing. Here it
is occasionally agitated by raking from the lower to the upper end of
the trough as the current carries it downward, and the apple seeds
becoming disengaged drop to the bottom into still water, while the pulp
floats away upon the stream. A succession of troughs serves to remove
nearly all the seeds. The value of the apple seeds thus saved is
sufficient to pay the daily wages of all the hands employed in the whole
establishment. The apples are measured in the wagon box, one and a half
cubic feet being accounted a bushel.
This mill ordinarily employs about six men: One general superintendent,
who buys and measures the apples, keeps time books, attends to all the
accounts and the working details of the mill, and acts as cashier; one
sawyer, who manufactures lumber for the local market and saws the slabs
into short lengths suitable for the furnace; one cider maker, who grinds
the apples and attends the presses; one jelly maker, who attends the
defecator, evaporator, and mixing tub, besides acting as his own fireman
and engineer; one who attends the apple seed troughs and acts as general
helper, and one man-of-all-work to pack, ship and assist whenever
needed. The establishment was erected late in the season of 1880,
and manufactured that year about forty-five tons of jelly, besides
considerable cider exchanged to the farmers for apples, and some boiled
cider.
The price paid for apples in 1880, when the crop was superabundant, was
six to eight cents per bushel; in 1881, fifteen cents. The proprietor
hopes next year to consume 100,000 bushels. These institutions are
important to the farmer in that they use much fruit not otherwise
valuable and very perishable. Fruit so crabbed and gnarled as to have no
market value, and even frozen apples, if delivered while yet solid, can
be used. (Such apples are placed in the water while frozen, the water
draws the frost sufficiently to be grated, and passing through the press
and evaporator before there is time for chemical change, they are found
to make very good jelly. They are valuable to the consumer by converting
the perishable, cheap, almost worthless crop of the bearing and abundant
years into such enduring form that its consumption may be carried over
to years of scarcity and furnish healthful food in cheap and pleasant
form to many who would otherwise be deprived; and lastly, they are of
great interest to society, in that they give to cider twice the value
for purposes of food that it has or can have, even to the manufacturer,
for use as a beverage and intoxicant.
* * * * *
IMPROVED GRAPE BAGS.
It stands to reason that were our summers warmer we should be able to
grow grapes successfully on open walls; it is therefore probable that
a new grape bag, the invention of M. Pelletier, 20 Rue de la Banque,
Paris, intended to serve a double purpose, viz., protecting the fruit
and hastening its maturity, will, when it becomes known, be welcomed in
this country. It consists of a square of curved glass so fixed to
the bag that the sun's rays are concentrated upon the fruit, thereby
rendering its ripening more certain in addition to improving its quality
generally. The glass is affixed to the bag by means of a light iron wire
support. It covers that portion of it next the sun, so that it increases
the amount of light and warms the grapes without scorching them, a
result due to the convexity of the glass and the layer of air between it
and the bag. M. Pelletier had the idea of rendering these bags cheaper
by employing plain squares instead of curved ones, but the advantage
thus obtained was more than counterbalanced by their comparative
inefficacy. In practice it was found that the curved squares gave an
average of 7 deg. more than the straight ones, while there was a difference
of 10 deg. when the bags alone were used, thus plainly demonstrating the
practical value of the invention.
Whether these glass-fronted bags would have much value in the case of
grapes grown under glass in the ordinary way is a question that can only
be determined by actual experiment; but where the vines are on walls,
either under glass screens or in the open air, so that the bunches feel
the full force of the sun's rays, there can be no doubt as to their
utility, and it is probable that by their aid many of the continental
varieties which we do not now attempt to grow in the open, and which are
scarcely worthy of a place under glass, might be well ripened. At
any rate we ought to give anything a fair trial which may serve to
neutralize, if only in a slight degree, the uncertainty of our summers.
As it is, we have only about two varieties of grapes, and these not the
best of the hardy kinds, as regards flavor and appearance, that ripen
out of doors, and even these do not always succeed. We know next to
nothing of the many really well-flavored kinds which are so much
appreciated in many parts of the Continent. The fact is, our outdoor
culture of grapes offers a striking contrast to that practiced under
glass, and although our comparatively sunless and moist climate affords
some excuse for our shortcomings in this respect, there is no valid
reason for the utter want of good culture which is to be observed in a
general way.
[Illustration: GRAPE BAG.--OPEN.]
Given intelligent training, constant care in stopping the laterals, and
checking mildew as well as thinning the berries, allowing each bunch to
get the full benefit of sun and air, and I believe good eatable grapes
would often be obtained even in summers marked by a low average
temperature.
[Illustration: GRAPE BAG.--CLOSED.]
If, moreover, to a good system of culture we add some such mechanical
contrivance as that under notice whereby the bunches enjoy an average
warmth some 10 deg. higher than they otherwise would do, we not only insure
the grapes coming to perfection in favored districts, but outdoor
culture might probably be practiced in higher latitudes than is now
practicable.
[Illustration: CURVED GLASS FOR FRONT OF BAG.]
The improved grape bag would also offer great facilities for destroying
mildew or guarantee the grapes against its attacks, as a light dusting
administered as soon as the berries were fairly formed would suffice for
the season, as owing to the glass protecting the berries from driving
rains, which often accompany south or south-west winds in summer and
autumn, the sulphur would not be washed off.
[Illustration: CURVED GLASS FIXED ON BAG.]
The inventor claims, and we should say with just reason, that these
glass fronted bags would be found equally serviceable for the ripening
of pears and other choice fruits, and with a view to their being
employed for such a purpose, he has had them made of varying sizes and
shapes. In conclusion, it may be observed that, in addition to advancing
the maturity of the fruits to which they are applied, they also serve to
preserve them from falling to the ground when ripe.--J. COBNHILL, _in
the Garden_.
* * * * *
UTILIZATION OF SOLAR HEAT.
At a popular fete in the Tuileries Gardens I was struck with an
experiment which seems deserving of the immediate attention of the
English public and military authorities.
Among the attractions of the fete was an apparatus for the concentration
and utilization of solar heat, and, though the sun was not very
brilliant, I saw this apparatus set in motion a printing machine which
printed several thousand copies of a specimen newspaper entitled the
_Soleil Journal_.
The sun's rays are concentrated in a reflector, which moves at the
same rate as the sun and heats a vertical boiler, setting the motive
steam-engine at work. As may be supposed, the only object was to
demonstrate the possibility of utilizing the concentrated heat of the
solar rays; but I closely examined it, because the apparatus seems
capable of great utility in existing circumstances. Here in France,
indeed, there is a radical drawback--the sun is often overclouded.
Thousands of years ago the idea of utilizing the solar rays must have
suggested itself, and there are still savage tribes who know no other
mode of combustion; but the scientific application has hitherto been
lacking. This void this apparatus will fill up. About fifteen years ago
Professor Mouchon, of Tours, began constructing such an apparatus, and
his experiments have been continued by M. Pifre, who has devoted much
labor and expense to realizing M. Mouchou's idea. A company has now come
to his aid, and has constructed a number of apparatus of different sizes
at a factory which might speedily turn out a large number of them. It is
evident that in a country of uninterrupted sunshine the boiler might be
heated in thirty or forty minutes. A portable apparatus could boil two
and one-half quarts an hour, or, say, four gallons a day, thus supplying
by distillation or ebullition six or eight men. The apparatus can be
easily carried on a man's back, and on condition of water, even of the
worst quality, being obtainable, good drinking and cooking water is
insured. M. De Rougaumond, a young scientific writer, has just published
an interesting volume on the invention. I was able yesterday to verify
his statements, for I saw cider made, a pump set in motion, and coffee
made--in short, the calorific action of the sun superseding that of
fuel. The apparatus, no doubt, has not yet reached perfection, but as it
is it would enable the soldier in India or Egypt to procure in the field
good water and to cook his food rapidly. The invention is of especial
importance to England just now, but even when the Egyptian question is
settled the Indian troops might find it of inestimable value.
Red tape should for once be disregarded, and a competent commission
forthwith sent to 30 Rue d'Assas, with instructions to report
immediately, for every minute saved may avoid suffering for Englishmen
fighting abroad for their country. I may, of course, be mistaken, but
a commission would decide, and if the apparatus is good the slightest
delay in its adoption would be deplorable.--_Paris Correspondence London
Times_.
* * * * *
HOW TO ESTABLISH A TRUE MERIDIAN.
[Footnote: A paper read before the Engineers' Club of Philadelphia.]
By PROFESSOR L. M. HAUPT.
INTRODUCTORY.
The discovery of the magnetic needle was a boon to mankind, and has been
of inestimable service in guiding the mariner through trackless waters,
and the explorer over desert wastes. In these, its legitimate uses, the
needle has not a rival, but all efforts to apply it to the accurate
determination of permanent boundary lines have proven very
unsatisfactory, and have given rise to much litigation, acerbity, and
even death.
For these and other cogent reasons, strenuous efforts are being made to
dispense, so far as practicable, with the use of the magnetic needle
in surveying, and to substitute therefor the more accurate method of
traversing from a true meridian. This method, however, involves a
greater degree of preparation and higher qualifications than are
generally possessed, and unless the matter can be so simplified as to be
readily understood, it is unreasonable to expect its general application
in practice.
Much has been written upon the various methods of determining, the
true meridian, but it is so intimately related to the determination of
latitude and time, and these latter in turn upon the fixing of a true
meridian, that the novice can find neither beginning nor end. When to
these difficulties are added the corrections for parallax, refraction,
instrumental errors, personal equation, and the determination of the
probable error, he is hopelessly confused, and when he learns that time
may be sidereal, mean solar, local, Greenwich, or Washington, and he is
referred to an ephemeris and table of logarithms for data, he becomes
lost in "confusion worse confounded," and gives up in despair, settling
down to the conviction that the simple method of compass surveying is
the best after all, even if not the most accurate.
Having received numerous requests for information upon the subject, I
have thought it expedient to endeavor to prepare a description of the
method of determining the true meridian which should be sufficiently
clear and practical to be generally understood by those desiring to make
use of such information.
This will involve an elementary treatment of the subject, beginning with
the
DEFINITIONS.
The _celestial sphere_ is that imaginary surface upon which all
celestial objects are projected. Its radius is infinite.
The _earth's axis_ is the imaginary line about which it revolves.
The _poles_ are the points in which the axis pierces the surface of the
earth, or of the celestial sphere.
A _meridian_ is a great circle of the earth cut out by a plane passing
through the axis. All meridians are therefore north and south lines
passing through the poles.
From these definitions it follows that if there were a star exactly at
the pole it would only be necessary to set up an instrument and take a
bearing to it for the meridian. Such not being the case, however, we are
obliged to take some one of the near circumpolar stars as our object,
and correct the observation according to its angular distance from the
meridian at the time of observation.
For convenience, the bright star known as Ursae Minoris or Polaris, is
generally selected. This star apparently revolves about the north pole,
in an orbit whose mean radius is 1 deg. 19' 13",[1] making the revolution in
23 hours 56 minutes.
[Footnote 1: This is the codeclination as given in the Nautical Almanac.
The mean value decreases by about 20 seconds each year.]
During this time it must therefore cross the meridian twice, once above
the pole and once below; the former is called the _upper_, and the
latter the _lower meridian transit or culmination_. It must also pass
through the points farthest east and west from the meridian. The former
is called the _eastern elongation_, the latter the _western_.
An observation may he made upon Polaris at any of these four points,
or at any other point of its orbit, but this latter case becomes too
complicated for ordinary practice, and is therefore not considered.
If the observation were made upon the star at the time of its upper or
lower culmination, it would give the true meridian at once, but this
involves a knowledge of the true local time of transit, or the longitude
of the place of observation, which is generally an unknown quantity; and
moreover, as the star is then moving east or west, or at right angles to
the place of the meridian, at the rate of 15 deg. of arc in about one hour,
an error of so slight a quantity as only four seconds of time would
introduce an error of one minute of arc. If the observation be made,
however, upon either elongation, when the star is moving up or down,
that is, in the direction of the vertical wire of the instrument, the
error of observation in the angle between it and the pole will be
inappreciable. This is, therefore, the best position upon which to make
the observation, as the precise time of the elongation need not be
given. It can be determined with sufficient accuracy by a glance at the
relative positions of the star Alioth, in the handle of the Dipper,
and Polaris (see Fig. 1). When the line joining these two stars is
horizontal or nearly so, and Alioth is to the _west_ of Polaris, the
latter is at its _eastern_ elongation, and _vice versa_, thus:
[Illustration]
But since the star at either elongation is off the meridian, it will
be necessary to determine the angle at the place of observation to be
turned off on the instrument to bring it into the meridian. This angle,
called the azimuth of the pole star, varies with the latitude of the
observer, as will appear from Fig 2, and hence its value must be
computed for different latitudes, and the surveyor must know his
_latitude_ before he can apply it. Let N be the north pole of the
celestial sphere; S, the position of Polaris at its eastern elongation;
then N S=1 deg. 19' 13", a constant quantity. The azimuth of Polaris at the
latitude 40 deg. north is represented by the angle N O S, and that at 60 deg.
north, by the angle N O' S, which is greater, being an exterior angle
of the triangle, O S O. From this we see that the azimuth varies at the
latitude.
We have first, then, to _find the latitude of the place of observation_.
Of the several methods for doing this, we shall select the simplest,
preceding it by a few definitions.
A _normal_ line is the one joining the point directly overhead, called
the _zenith_, with the one under foot called the _nadir_.
The _celestial horizon_ is the intersection of the celestial sphere by a
plane passing through the center of the earth and perpendicular to the
normal.
A _vertical circle_ is one whose plane is perpendicular to the horizon,
hence all such circles must pass through the normal and have the zenith
and nadir points for their poles. The _altitude_ of a celestial object
is its distance above the horizon measured on the arc of a vertical
circle. As the distance from the horizon to the zenith is 90 deg., the
difference, or _complement_ of the altitude, is called the _zenith
distance_, or _co-altitude_.
The _azimuth_ of an object is the angle between the vertical plane
through the object and the plane of the meridian, measured on the
horizon, and usually read from the south point, as 0 deg., through west, at
90, north 180 deg., etc., closing on south at 0 deg. or 360 deg..
These two co-ordinates, the altitude and azimuth, will determine the
position of any object with reference to the observer's place. The
latter's position is usually given by his latitude and longitude
referred to the equator and some standard meridian as co-ordinates.
The _latitude_ being the angular distance north or south of the equator,
and the _longitude_ east or west of the assumed meridian.
We are now prepared to prove that _the altitude of the pole is equal to
the latitude of the place of observation_.
Let H P Z Q, etc., Fig. 2, represent a meridian section of the sphere,
in which P is the north pole and Z the place of observation, then H H
will be the horizon, Q Q the equator, H P will be the altitude of P,
and Q Z the latitude of Z. These two arcs are equal, for H C Z = P C
Q = 90 deg., and if from these equal quadrants the common angle P C Z be
subtracted, the remainders H C P and Z C Q, will be equal.
To _determine the altitude of the pole_, or, in other words, _the
latitude of the place_.
Observe the altitude of the pole star _when on the meridian_, either
above or below the pole, and from this observed altitude corrected for
refraction, subtract the distance of the star from the pole, or its
_polar distance_, if it was an upper transit, or add it if a lower.
The result will be the required latitude with sufficient accuracy for
ordinary purposes.
The time of the star's being on the meridian can be determined with
sufficient accuracy by a mere inspection of the heavens. The refraction
is _always negative_, and may be taken from the table appended by
looking up the amount set opposite the observed altitude. Thus, if the
observer's altitude should be 40 deg. 39' the nearest refraction 01' 07",
should be subtracted from 40 deg. 37' 00", leaving 40 deg. 37' 53" for the
latitude.
TO FIND THE AZIMUTH OF POLARIS.
As we have shown the azimuth of Polaris to be a function of the
latitude, and as the latitude is now known, we may proceed to find the
required azimuth. For this purpose we have a right-angled spherical
triangle, Z S P, Fig. 4, in which Z is the place of observation, P the
north pole, and S is Polaris. In this triangle we have given the polar
distance, P S = 10 deg. 19' 13"; the angle at S = 90 deg.; and the distance Z
P, being the complement of the latitude as found above, or 90 deg.--L.
Substituting these in the formula for the azimuth, we will have sin. Z =
sin. P S / sin P Z or sin. of Polar distance / sin. of co-latitude, from
which, by assuming different values for the co-latitude, we compute the
following table:
AZIMUTH TABLE FOR POINTS BETWEEN 26 deg. and 50 deg. N. LAT.
LATTITUDES
___________________________________________________________________
| | | | | | | |
| Year | 26 deg. | 28 deg. | 30 deg. | 32 deg. | 34 deg. | 36 deg. |
|______|_________|__________|_________|_________|_________|_________|
| | | | | | | |
| | deg. ' " | deg. ' " | deg. ' " | deg. ' " | deg. ' " | deg. ' " |
| 1882 | 1 28 05 | 1 29 40 | 1 31 25 | 1 33 22 | 1 35 30 | 1 37 52 |
| 1883 | 1 27 45 | 1 29 20 | 1 31 04 | 1 33 00 | 1 35 08 | 1 37 30 |
| 1884 | 1 27 23 | 1 28 57 | 1 30 41 | 1 32 37 | 1 34 45 | 1 37 05 |
| 1885 | 1 27 01 | 1 28 351/2 | 1 30 19 | 1 32 14 | 1 34 22 | 1 36 41 |
| 1886 | 1 26 39 | 1 28 13 | 1 29 56 | 1 31 51 | 1 33 57 | 1 36 17 |
|______|_________|__________|_________|_________|_________|_________|
| | | | | | | |
| Year | 38 deg. | 40 deg. | 42 deg. | 44 deg. | 46 deg. | 48 deg. |
|______|_________|__________|_________|_________|_________|_________|
| | | | | | | |
| | deg. ' " | deg. ' " | deg. ' " | deg. ' " | deg. ' " | deg. ' " |
| 1882 | 1 40 29 | 1 43 21 | 1 46 33 | 1 50 05 | 1 53 59 | 1 58 20 |
| 1883 | 1 40 07 | 1 42 58 | 1 46 08 | 1 49 39 | 1 53 34 | 1 57 53 |
| 1884 | 1 39 40 | 1 42 31 | 1 45 41 | 1 49 11 | 1 53 05 | 1 57 23 |
| 1885 | 1 39 16 | 1 42 07 | 1 45 16 | 1 48 45 | 1 52 37 | 1 56 54 |
| 1886 | 1 38 51 | 1 41 41 | 1 44 49 | 1 48 17 | 1 52 09 | 1 56 24 |
|______|_________|__________|_________|_________|_________|_________|
| | |
| Year | 50 deg. |
|______|_________|
| | |
| | deg. ' " |
| 1882 | 2 03 11 |
| 1883 | 2 02 42 |
| 1884 | 2 02 11 |
| 1885 | 2 01 42 |
| 1886 | 2 01 11 |
|______|_________|
An analysis of this table shows that the azimuth this year (1882)
increases with the latitude from 1 deg. 28' 05" at 26 deg. north, to 2 deg. 3' 11"
at 50 deg. north, or 35' 06". It also shows that the azimuth of Polaris at
any one point of observation decreases slightly from year to year. This
is due to the increase in declination, or decrease in the star's polar
distance. At 26 deg. north latitude, this annual decrease in the azimuth
is about 22", while at 50 deg. north, it is about 30". As the variation in
azimuth for each degree of latitude is small, the table is only computed
for the even numbered degrees; the intermediate values being readily
obtained by interpolation. We see also that an error of a few minutes of
latitude will not affect the result in finding the meridian, e.g., the
azimuth at 40 deg. north latitude is 1 deg. 43' 21", that at 41 deg. would be 1 deg. 44'
56", the difference (01' 35") being the correction for one degree of
latitude between 40 deg. and 41 deg.. Or, in other words, an error of one degree
in finding one's latitude would only introduce an error in the azimuth
of one and a half minutes. With ordinary care the probable error of the
latitude as determined from the method already described need not exceed
a few minutes, making the error in azimuth as laid off on the arc of an
ordinary transit graduated to single minutes, practically zero.
REFRACTION TABLE FOR ANY ALTITUDE WITHIN THE LATITUDE OF THE UNITED
STATES.
_____________________________________________________
| | | | |
| Apparent | Refraction | Apparent | Refraction |
| Altitude. | _minus_. | Altitude. | _minus_. |
|___________|______________|___________|______________|
| | | | |
| 25 deg. | 0 deg. 2' 4.2" | 38 deg. | 0 deg. 1' 14.4" |
| 26 | 1 58.8 | 39 | 1 11.8 |
| 27 | 1 53.8 | 40 | 1 9.3 |
| 28 | 1 49.1 | 41 | 1 6.9 |
| 29 | 1 44.7 | 42 | 1 4.6 |
| 30 | 1 40.5 | 43 | 1 2.4 |
| 31 | 1 36.6 | 44 | 0 0.3 |
| 32 | 1 33.0 | 45 | 0 58.1 |
| 33 | 1 29.5 | 46 | 0 56.1 |
| 34 | 1 26.1 | 47 | 0 54.2 |
| 35 | 1 23.0 | 48 | 0 52.3 |
| 36 | 1 20.0 | 49 | 0 50.5 |
| 37 | 1 17.1 | 50 | 0 48.8 |
|___________|______________|___________|______________|
APPLICATIONS.
In practice to find the true meridian, two observations must be made at
intervals of six hours, or they may be made upon different nights. The
first is for latitude, the second for azimuth at elongation.
To make either, the surveyor should provide himself with a good transit
with vertical arc, a bull's eye, or hand lantern, plumb bobs, stakes,
etc.[1] Having "set up" over the point through which it is proposed to
establish the meridian, at a time when the line joining Polaris and
Alioth is nearly vertical, level the telescope by means of the attached
level, which should be in adjustment, set the vernier of the vertical
arc at zero, and take the reading. If the pole star is about making its
_upper_ transit, it will rise gradually until reaching the meridian as
it moves westward, and then as gradually descend. When near the highest
part of its orbit point the telescope at the star, having an assistant
to hold the "bull's eye" so as to reflect enough light down the tube
from the object end to illumine the cross wires but not to obscure the
star, or better, use a perforated silvered reflector, clamp the tube in
this position, and as the star continues to rise keep the _horizontal_
wire upon it by means of the tangent screw until it "rides" along this
wire and finally begins to fall below it. Take the reading of the
vertical arc and the result will be the observed altitude.
[Footnote 1: A sextant and artificial horizon may be used to find the
_altitude_ of a star. In this case the observed angle must be divided by
2.]
ANOTHER METHOD.
It is a little more accurate to find the altitude by taking the
complement of the observed zenith distance, if the vertical arc has
sufficient range. This is done by pointing first to Polaris when at
its highest (or lowest) point, reading the vertical arc, turning the
horizontal limb half way around, and the telescope over to get another
reading on the star, when the difference of the two readings will be the
_double_ zenith distance, and _half_ of this subtracted from 90 deg. will be
the required altitude. The less the time intervening between these two
pointings, the more accurate the result will be.
Having now found the altitude, correct it for refraction by subtracting
from it the amount opposite the observed altitude, as given in the
refraction table, and the result will be the latitude. The observer must
now wait about six hours until the star is at its western elongation,
or may postpone further operations for some subsequent night. In the
meantime he will take from the azimuth table the amount given for his
date and latitude, now determined, and if his observation is to be made
on the western elongation, he may turn it off on his instrument, so
that when moved to zero, _after_ the observation, the telescope will be
brought into the meridian or turned to the right, and a stake set by
means of a lantern or plummet lamp.
[Illustration]
It is, of course, unnecessary to make this correction at the time of
observation, for the angle between any terrestrial object and the star
may be read and the correction for the azimuth of the star applied at
the surveyor's convenience. It is always well to check the accuracy of
the work by an observation upon the other elongation before putting in
permanent meridian marks, and care should be taken that they are not
placed near any local attractions. The meridian having been established,
the magnetic variation or declination may readily be found by setting
an instrument on the meridian and noting its bearing as given by the
needle. If, for example, it should be north 5 deg. _east_, the variation is
west, because the north end of the needle is _west_ of the meridian, and
_vice versa_.
_Local time_ may also be readily found by observing the instant when the
sun's center[1] crosses the line, and correcting it for the equation of
time as given above--the result is the true or mean solar time. This,
compared with the clock, will show the error of the latter, and by
taking the difference between the local lime of this and any other
place, the difference of longitude is determined in hours, which can
readily be reduced to degrees by multiplying by fifteen, as 1 h. = 15 deg..
[Footnote 1: To obtain this time by observation, note the instant of
first contact of the sun's limb, and also of last contact of same, and
take the mean.]
APPROXIMATE EQUATION OF TIME.
_______________________
| | |
| Date. | Minutes. |
|__________|____________|
| | |
| Jan. 1 | 4 |
| 3 | 5 |
| 5 | 6 |
| 7 | 7 |
| 9 | 8 |
| 12 | 9 |
| 15 | 10 |
| 18 | 11 |
| 21 | 12 |
| 25 | 13 |
| 31 | 14 |
| Feb. 10 | 15 |
| 21 | 14 | Clock
| 27 | 13 | faster
| M'ch 4 | 12 | than
| 8 | 11 | sun.
| 12 | 10 |
| 15 | 9 |
| 19 | 8 |
| 22 | 7 |
| 25 | 6 |
| 28 | 5 |
| April 1 | 4 |
| 4 | 3 |
| 7 | 2 |
| 11 | 1 |
| 15 | 0 |
| |------------|
| 19 | 1 |
| 24 | 2 |
| 30 | 3 |
| May 13 | 4 | Clock
| 29 | 3 | slower.
| June 5 | 2 |
| 10 | 1 |
| 15 | 0 |
| |------------|
| 20 | 1 |
| 25 | 2 |
| 29 | 3 |
| July 5 | 4 |
| 11 | 5 |
| 28 | 6 | Clock
| Aug. 9 | 5 | faster.
| 15 | 4 |
| 20 | 3 |
| 24 | 2 |
| 28 | 1 |
| 31 | 0 |
| |------------|
| Sept. 3 | 1 |
| 6 | 2 |
| 9 | 3 |
| 12 | 4 |
| 15 | 5 |
| 18 | 6 |
| 21 | 7 |
| 24 | 8 |
| 27 | 9 |
| 30 | 10 |
| Oct. 3 | 11 |
| 6 | 12 |
| 10 | 13 |
| 14 | 14 |
| 19 | 15 |
| 27 | 16 | Clock
| Nov. 15 | 15 | slower.
| 20 | 14 |
| 24 | 13 |
| 27 | 12 |
| 30 | 11 |
| Dec. 2 | 10 |
| 5 | 9 |
| 7 | 8 |
| 9 | 7 |
| 11 | 6 |
| 13 | 5 |
| 16 | 4 |
| 18 | 3 |
| 20 | 2 |
| 22 | 1 |
| 24 | 0 |
| |------------|
| 26 | 1 |
| 28 | 2 | Clock
| 30 | 3 | faster.
|__________|____________|
* * * * *
THE OCELLATED PHEASANT.
The collections of the Museum of Natural History of Paris have just been
enriched with a magnificent, perfectly adult specimen of a species of
bird that all the scientific establishments had put down among their
desiderata, and which, for twenty years past, has excited the curiosity
of naturalists. This species, in fact, was known only by a few caudal
feathers, of which even the origin was unknown, and which figured in the
galleries of the Jardin des Plantes under the name of _Argus ocellatus_.
This name was given by J. Verreaux, who was then assistant naturalist at
the museum. It was inscribed by Prince Ch. L. Bonaparte, in his Tableaux
Paralleliques de l'Ordre des Gallinaces, as _Argus giganteus_, and a
few years later it was reproduced by Slater in his Catalogue of the
Phasianidae, and by Gray is his List of the Gallinaceae. But it was not
till 1871 and 1872 that Elliot, in the Annals and Magazine of Natural
History, and in a splendid monograph of the Phasianidae, pointed out
the peculiarities that were presented by the feathers preserved at the
Museum of Paris, and published a figure of them of the natural size.
The discovery of an individual whose state of preservation leaves
nothing to be desired now comes to demonstrate the correctness of
Verreaux's, Bonaparte's, and Elliot's suppositions. This bird, whose
tail is furnished with feathers absolutely identical with those that
the museum possessed, is not a peacock, as some have asserted, nor an
ordinary Argus of Malacca, nor an argus of the race that Elliot named
_Argus grayi_, and which inhabits Borneo, but the type of a new genus of
the family Phasianidae. This Gallinacean, in fact, which Mr. Maingonnat
has given up to the Museum of Natural History, has not, like the common
Argus of Borneo, excessively elongated secondaries; and its tail is not
formed of normal rectrices, from the middle of which spring two very
long feathers, a little curved and arranged like a roof; but it consists
of twelve wide plane feathers, regularly tapering, and ornamented with
ocellated spots, arranged along the shaft. Its head is not bare, but is
adorned behind with a tuft of thread-like feathers; and, finally, its
system of coloration and the proportions of the different parts of its
body are not the same as in the common argus of Borneo. There is reason,
then, for placing the bird, under the name of _Rheinardius ocellatus_,
in the family Phasianidae, after the genus _Argus_ which it connects,
after a manner, with the pheasants properly so-called. The specific name
_ocellatus_ has belonged to it since 1871, and must be substituted for
that of _Rheinardi_.
The bird measures more than two meters in length, three-fourths of which
belong to the tail. The head, which is relatively small, appears to be
larger than it really is, owing to the development of the piliform tuft
on the occiput, this being capable of erection so as to form a crest
0.05 to 0.06 of a meter in height. The feathers of this crest are
brown and white. The back and sides of the head are covered with downy
feathers of a silky brown and silvery gray, and the front of the neck
with piliform feathers of a ruddy brown. The upper part of the body is
of a blackish tint and the under part of a reddish brown, the whole
dotted with small white or _cafe-au-lait_ spots. Analogous spots are
found on the wings and tail, but on the secondaries these become
elongated, and tear-like in form. On the remiges the markings are quite
regularly hexagonal in shape; and on the upper coverts of the tail
and on the rectrices they are accompanied with numerous ferruginous
blotches, some of which are irregularly scattered over the whole surface
of the vane, while others, marked in the center with a blackish spot,
are disposed in series along the shaft and resemble ocelli. This
similitude of marking between the rectrices and subcaudals renders the
distinction between these two kinds of feathers less sharp than in many
other Gallinaceans, and the more so in that two median rectrices are
considerably elongated and assume exactly the aspect of tail feathers.
[Illustration: THE OCELLATED PHEASANT (_Rheinardius ocellatus_).]
The true rectrices are twelve in number. They are all absolutely plane,
all spread out horizontally, and they go on increasing in length
from the exterior to the middle. They are quite wide at the point of
insertion, increase in diameter at the middle, and afterward taper to
a sharp point. Altogether they form a tail of extraordinary length and
width which the bird holds slightly elevated, so as to cause it to
describe a graceful curve, and the point of which touches the soil. The
beak, whose upper mandible is less arched than that of the pheasants,
exactly resembles that of the arguses. It is slightly inflated at the
base, above the nostrils, and these latter are of an elongated-oval
form. In the bird that I have before me the beak, as well as the feet
and legs, is of a dark rose-color. The legs are quite long and are
destitute of spurs. They terminate in front in three quite delicate
toes, connected at the base by membranes, and behind in a thumb that is
inserted so high that it scarcely touches the ground in walking. This
magnificent bird was captured in a portion of Tonkin as yet unexplored
by Europeans, in a locality named Buih-Dinh, 400 kilometers to the south
of Hue.--_La Nature_.
* * * * *
THE MAIDENHAIR TREE.
The Maidenhair tree--Gingkgo biloba--of which we give an illustration,
is not only one of our most ornamental deciduous trees, but one of the
most interesting. Few persons would at first sight take it to be a
Conifer, more especially as it is destitute of resin; nevertheless,
to that group it belongs, being closely allied to the Yew, but
distinguishable by its long-stalked, fan-shaped leaves, with numerous
radiating veins, as in an Adiantum. These leaves, like those of the
larch but unlike most Conifers, are deciduous, turning of a pale yellow
color before they fall. The tree is found in Japan and in China, but
generally in the neighborhood of temples or other buildings, and is, we
believe, unknown in a truly wild state. As in the case of several other
trees planted in like situations, such as Cupressus funebris, Abies
fortunei, A. kaempferi, Cryptomeria japonica, Sciadopitys verticillata,
it is probable that the trees have been introduced from Thibet, or
other unexplored districts, into China and Japan. Though now a solitary
representative of its genus, the Gingkgo was well represented in the
coal period, and also existed through the secondary and tertiary epochs,
Professor Heer having identified kindred specimens belonging to sixty
species and eight genera in fossil remains generally distributed through
the northern hemisphere. Whatever inference we may draw, it is at least
certain that the tree was well represented in former times, if now it
be the last of its race. It was first known to Kaempfer in 1690, and
described by him in 1712, and was introduced into this country in the
middle of the eighteenth century. Loudon relates a curious tale as
to the manner in which a French amateur became possessed of it. The
Frenchman, it appears, came to England, and paid a visit to an English
nurseryman, who was the possessor of five plants, raised from Japanese
seeds. The hospitable Englishman entertained the Frenchman only too
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