Vol. XXV. No. 11.] 
POPULAR SOIEI^OE NEWS. 
163 
methods of suspending a barrel, either horizon- 
tally or vertically; while for a bag or sack the 
efficient fastening shown in 7, or the simpler one 
shown in 8, will be found secure and convenient. 
All the above fastenings can be made from a 
single piece of rope, and their construction will 
be evident from an inspection of the engravings. 
<^» 
[New York Sun.] 
A PKOBLEM. 
A CY'Ci-ONE demolished the barn of Sam Mc- 
Pherson, of Monroe Count}', Kentucky, on July 
24. Seventy-seven days later the workmen who 
were clearing away the debris liberated a hen 
that liad been cooped in narrow quarters formed 
by fallen boards and timbers. In the course of 
her impiisonmeut she had laid an egg, hatched it, 
and eaten the chicken all but the feathers and 
bones. Apparently she had nothing else to eat. 
Here rises an interesting question for econo- 
mists: Did it pay the hen to hatch the egg? 
■■ In times of dire necessity self-preservation be- 
comes paramount. Castaway sailors kill their 
weaker fellows and eat them. Famished brutes 
devour even their own oflspring. Probably no 
sentimental considerations prevented this hen 
from coolly calculating whether she could 
lengthen her days and increase her chances of 
rescue by hatching out the egg and eating the 
chicken, or whether her cliances would be better 
if she ate the egg while it was fresh. Nobody 
can say that she did not consider this grave prob- 
lem in all its aspects, and that her survival during 
the seventy-seven days that elapsed before she 
was rescued was not the result of her decision in 
accordance with scientific ti-uths. 
If there was nothing to eat in the fortuitously 
improvised crop, did the hatched chicken contain 
more nutriment than the unhatched egg? If 
more, was the gain at the expense of the hen, and 
did it cost her more than she received in the way 
of increased nutriment? Warmth is necessary to 
incubation. Heat can be produced only by the 
outlay of energy. If there was more food in the 
chicken than in the egg, was the excess sufficient 
to restore to the hen the energy spared in hatch- 
ing the egg? And if so, was the excess still great 
enough to make up for the loss of edible substance 
through the conversion of part of the egg into 
bones and feathers? 
These questions cannot be dismissed by scien- 
tific men as trivial. They are worthy of the pro- 
foundest thought of savants. Certainly no other 
hen ever was brought face to face with questions 
from her point of view more momentous,- or which 
called for greater nicety in the weighing of them. 
TO KESTORE FADED OR OBLITERATED 
INK. 
The following suggestions are from Haldane's 
" Workshop Receipts " : 
1. Wash in warm water to remove salt U the 
paper has been immersed in sea-water, and then 
soak in a solution of gallic acid, three grains to 
the ounce of water. 
2. Wash in clean water and soak in solution of 
ferrous sulphate, ten grains to the ounce. 
3. Apply a solution of potassium ferrocyanide 
with a brush, when the writing will appear in 
blue, if any iron is left of the original ink. 
4. Falsified Writing. — Gobert has found that if 
writing is ever so carefully scratched out, there 
are still left sufticient traces of the oxide of iron 
in the ink to become visible in a photographic 
copy. Light reflected from paper that has not 
been written on acts in a diflerent way on the 
photographic materials from that reflected from 
places which have been once covered with ink. 
SOME TELESCOPES IN THE UNITED 
STATES. 
Dr. Wm. H. Knight gives in a recent number 
of the Sidereal Messenger a list of over one hun- 
dred telescopes, with names of owners, makers, 
etc. The list includes only those instruments of 
which the aperture is four inches or upward. 
The twelve largest refracting telescopes are 
those of the Lick Observatory with an aperture of 
36 inches, Yale University 28, U. S. Naval 26, 
Leander McCormick 26, Princeton 23, Denver 20, 
Smithsonian 20, Dearborn 18.5, "Carletou College 
16.2, Warner 16, Washburn 1.5.5, and Harvard 15. 
The largest reflecting telescopes are those of 
Harvard College, 28 inches, and Rev. Dr. John 
Peate, 22. Dr. Peate, who is an amateur maker, 
is now finishing up a 30H inch silver-on-glass 
mirror, which will be presented to the Allegheny 
College at Meadville. When mounted it will be 
the largest reflecting telescope in this country. 
There are numerous reflectors made by Brasliear 
from 9 to 12 inches in diameter. 
The Clarks are now grinding an object glass of 
40 inches for a telescope to be mounted in an 
observatory yet to be built upon Mount Wilson in 
Southern California. 
Though the Lick Observatory possesses the 
largest telescope at present. Harvard College has 
the best equipped observatory for general astrono- 
mical work in America, and one of the best in the 
world. 
In foreign countries the largest refractors are 
those at Pulkowa, near St. Petersburg, 30 inches, 
Nice 29.75, Vienna 26.75, Gateshead, near London, 
25, and Paris 23.6. 
The largest reflectors are those of Lord Rosse, 
in Ireland, 72 inches, Melbourne 48, Paris 47, 
Mr. Common's, in England, 37.5, another of Lord 
Rosse 36, Toulouse 32.4, Marseilles, 31.5, Green- 
wich 28, and Cambridge 24. 
INDUSTRIAL MEMORANDA. 
For a good solution for removing the blue from 
steel so as to leave as clean as before coloring, try 
acetic acid, or solution of chloride of tin (stannous 
chloride) . 
Black Brass. — Brass may be colored black by 
repeatedly coating the cleansed metal with a mod- 
erately warm solution of nitrate of copper. Heat- 
ing over a charcoal fire follows. Finally the tone 
is heightened by rubbing with olive oil. 
An Aluminium Steamboat is now running 
on the Lake of Ziirich, Switzerland. The boat 
weighs only about half a ton, or about half the 
weight of an ordinary boat of the same size. It 
was built at Zurich, the metal having been fur- 
nished by the aluminium works of ScMaff"hausen. 
The boat carries eight persons, and, with a two 
horse-power petroleum engine, easily makes six 
miles an hour. 
To Make Skeleton Leaves. — Soak in rain 
water for some weeks, remove by floating upon a 
card, and very gently remove upper skin with a 
soft cameVs-liair brush. Float in water and catch 
on a card with the other side uppermost, and re- 
move other skin and pulp. A stiff' brush may be 
needed, to be used by dabbing. Do not touch 
with finger. Finally wash well, bleach with javelle 
water, wash and dry. 
Testing Firearms in Europe. — There are in 
Europe five "proving houses," or testing places 
for firearms. Of the Birmingham and London 
proof-houses many people have heard. ITie others 
are at St. Etienne, in the south of France; at Fel- 
lah, in Austria; and at Liege, in Belgium. The 
latter, however, is by far the largest establishment 
of its Ivind. It is ofl[icially stated that the Liege 
proof-house now consumes between 3,000,000 and 
4,000,000 cartridges and over forty tons of gun- 
powder a year. 
A Curious Property of Sulphur. — M. Charles 
Lepierre states that in demonstrating that sulphur, 
melted at about 115° C, can be cooled in paper, he 
happened to use a lithographed card of which the 
edges were tuined up. Upon taking away the 
card he discovered that the lithographed charac- 
ters were clearly and distinctly impressed upon 
the cooled surface of the sulphur, and remained 
after hard friction and washing. By repeated 
experiments he has been able to get very fine 
results, removing the paper each time by a mere 
washing and rubbing process. Ho finds that sul- 
phur will receive impressions from and reproduce 
faithfully characters or designs in ordinary graph- 
ite crayon, colored crayons, writing-ink, typo- 
graphical inks, china ink, lithographic inks (col- 
ored or uncolored), and others. He remarks, too, 
that it will reproduce with remarkable exactitude 
geographical maps. 
SCIENTIFIC BREVITIES. 
During the deep borings for rock salt at Asch- 
ersleben, potassium salts have been found at a 
depth of 1,050 feet, and works have been erected 
in consequence. 
On the summit of Ben Lomond may be seen the 
smallest tree that grows in Great Britain. It is 
known as the dwarf willow, and is, when mature, 
only about two inches in height. 
Of the entire human race, 500,000,000 are well 
clothed, that is, they wear garments of some kind ; 
250,000,000 habitually go naked, and 700,000,000 
only cover parts of the body; 500,000,000 live in 
houses, 700,000,000 in huts and caves, and 250,- 
000,000 virtually have no shelter. 
A Reaction of Carbonic Oxide. — If a few 
bubbles of carbonic oxide are passed into a weak 
and cold solution of ammoniac.al silver nitrate, the 
liquid immediately assumes a brown color, and at 
the boiling-point the silver is quickly reduced, 
according to M. Berthelot in Compt. Rend. 112, 
597. The action takes place also with an aqueous 
solution of the gas, and is extremely delicate, not 
being hindered even by the admixture of a large 
amount of air. This property of carbonic oxide 
is the more interesting, seefhg that the solution is 
not reduced by alkaline formates, nor by pure hy- 
drogen. 
Thunder-storms.— A German periodical gives 
statistics concerning the frequency of thunder- 
storms in various regions of the world. Java has 
thunder-storms on the average 97 days in the 
year; Sumatra, 86; Hindostan, 56; Borneo, 54; 
the Gold Coast, 52 ; Rio de Janeiro, 51 ; Italy, 38 ; 
West Indies, 36 ; South Guinea, 32 ; Buenos Ayres, 
Canada, and Austria, 23 ; Baden, Wurtemberg, and 
Hungary, 22; Silesia, Bavaria, and Belgium, 21; 
Holland, 18 ; Saxony and Brandenburg, 17 ; France, 
Austria, and South Russia, 16 ; Spain and Portu- 
gal, 15 ; Sweden and Finland, 8 ; England and the 
high Swiss mountains, 7; Norway, 4; Cairo, 3. 
In East Turkestan, as well as in the extreme 
north, there are almost no thunder-storms. The 
northern limits of the thunder-storms are Cape 
Ogle, northern part of North America, Iceland, 
Novaja Semelja, and the coast of the Siberian ice 
sea. 
