THE YOUNG SCIENTIST. 
353 
pipe. Of Bun sen burner, and fill the tube witli 
pure, clean, dry mercury, excluding all bubbles 
of air. Now place your finger over the open end 
of the tube, and cautiously insert it in a small 
cistern or vessel partially filled with mercury. 
Do not remove your finger until the end of tlie 
tube which it covers is saiely below the surface of 
the mercury in the vessel. When the tube is thus 
inserted, remove your finger, and the contents 
will fall until the height of the mercury is nearly 
30 ins. above the level of the mercury in the cis- 
tern beneath. In the barometer the mercury 
never rises above 31 inches, and seldom falls be- 
low 27. The tube may be fitted into a grooved 
wooden case, the scale attached in the proper 
place, and the final adjustment made by com- 
parison with a correct instrument.— King. 
135. F. K.— A beginner need not worry himself 
about the points of a violin. Learn to play first, 
and then, when you understand what you are 
about, go in for an "old master" if you please; 
but most of the merits of such instruments are 
imaginary, and the copies are just as good. In 
fact, nine-tenths of the Amatis, Stradivaris, 
Guarneris, and Bergonzis have been made in 
Paris, cooked in Brussels, and labelled in Lam- 
beth, to be "picked up as ba.rgains" in New 
York, Boston, or Philadelphia.— Music. 
136. Puzzled.— To bore a hole through a glass 
plate, make your drill white-hot, and then plunge 
it into mercury. Use camphor dissolved in 
spirits of turpentine to lubricate with, and you 
will get through the glass as easily as through a 
piece of mahogany. There are several other 
ways to drill holes in glass, just as simple. See 
"Workshop Companion," price 35 cents.— Old 
Beadee. 
137. Daisy.— We cannot prescribe for your pet 
dog as we do not know its ailment. In asking 
us to prescribe a method of treatment for any pet 
animal, whether bird or beast, our readers would 
do well to mention how it has been fed. Feed 
your canary only on canary seed and rape, two 
parts of the former to one of the latter. Give three 
drops of castor-oil every week; put a rusty nail 
in the water for a fortnight, and annoint the 
naked parts once a day with pure salad-oil. 
138. Daisy.— 1. For dandruff get a pomade as 
follows:— Nitric oxide of mercury ointment, one 
part; ordinary pomade, four parts; rub in night 
and morning, not on the hair, but into the scalp ; 
wash twice a week with carbolic soap; take a 
little sulphur internally thr^e times a week, and, 
if the health be low. a course of iron and quinine. 
2. Grease spots may be taken out by placing 
pieces of brown paper over them, and pressing 
with a hot iron as long as the bits of paper will 
absorb the grease. 3. Depends entirely on the 
kind of ink and color of cloth. Spirits of salt will 
remove some. 
139. Cyclist,— 1. The earliest notice of veloci- 
pedes is said to be that by Blanchard on July 17, 
1779. The first bicycle ever made a,nd run suc- 
cessfully was invented and built by a Scotchman. 
Gavin Dalzell, of Desmahagow, in 1836. The 
indiarubber tyres were the invention of Mr. E. A. 
Gowper. 2. Plated machines are almost as difR- 
<^ult to keep properly clean as bright ones. 3. 
Xeep a pin down the nozzle of your oil-can, and 
the aperture will always keep clear; but do not 
use oil, try glycerine instead.— Bicycle, 
140. Faemee Boy.— a horse will travel 400 yds. 
in 4M minutes at a walk. 400 yds. in 2 minutes at 
a trot, and 400 yds. in 1 minute at a gallop. The 
usual work of a horse is taken at 22,500 lbs. raised 
1 foot per minute, for 8 hours per day. A horse 
will carry 250 lbs. 25 miles per day of 8 hours. An 
average draught-horse will draw 1,600 lbs. 23 
miles per day on a level road, weight of wagon 
included. The average weight of a horse is 1.000 
lbs. : his strength is equal to that of 5 men. In a 
horse mill moving at 3 feet per second, track 25 
feet diameter, he exerts with the machine the 
T>ower of 4M horses. The greatest amount a 
horse can pull in a horizontal line is 900 lbs. ; but 
he can only do this momentarily, in continued 
exertion, probably half of this is the limit. He 
attains his growth in 5 years, will live 25; aver- 
age, 16 years. A horse will live 25 days on water 
without solid food. 17 days without eating or 
drinking, but only 5 days on solid food without 
drinking.— Jockey. 
141. Little Maiden.— "The onyx stone, on 
which, the most valuable cameos are cut, is found 
in such plenty on the Uruguay Eiver in Brazil 
that ships often take it for ballast," said a cameo 
cutter. " Some of it has been found in Germany, 
where much of the cutting is done. The market 
is flooded with cheap and imperfect cameos, the 
work of apprentices, yet there is a fair demand 
for new work at good prices, especially for por- 
traits. The art of cameo cutting is very old, and 
some of the specimens of Koman work done 
2,000 years ago are exquisite in tracery and de- 
sign. They are produced by an extraordinary 
amount of labor, unaided by the modern im- 
provements in tools. Such work was then done 
for monarchs or very wealthy persons, and a cut- 
ting requiring a year was a very common thing. 
The same quality of work is now within the 
reach of persons of moderate means. Three fair 
looking cameo cuttings, suitable for mounting as 
breast pin and earrings may be bought for $8. 
But cameo portraits cost from $50 to $250, accord- 
ing to size, and the stone"'for the latter would be 
worth about $70. 
"A raised cutting on any stone is called a cameo; 
when the device is sunk it is called an intaglio. 
The onyx is preferred for cameos above all stones, 
because it comes in layers of tw^o colors. The com- 
binations are black and white, black and cream, 
i-ed and white, and dark brown, called the sar- 
donyx. The advantage of a cameo portrait is 
that it will la.st forever. The stone is so hard 
that it can be cut only with diamond dust. The 
process of cutting consists of holding the stone 
up to revolving drills whose soft steel ends are 
covered with diamond dust. The utmost patience 
and caution, and delicate manipulation are re- 
quired to grind off the upper layer of stone. A 
mistake is fatal to the work. No steel can be 
made hard enough to drill the onyx. Even 
chrome steel will not doit, and that is so hard 
that a drill made from it will cut through an 
ordinary file. No acid will affect the onyx, and it 
will stand the greatest heat of the furnace if the 
heat be applied gradually, so as to prevent crack- 
ing.' '— HiSTOEICUS. 
142. Answer to Query No. 66. for May, 1883. 
How many times has the end of the world been 
predicted by men of more or less weight? Are 
there any such doleful predictions hanging over 
us now? If not too late to answer I offer this. 
It would be difficult to say just how many have 
predicted the "end of the world," but it is true 
that many have done so; some of them being 
sober, thoughtful men, and not to be condemned 
as fanatical, because others have been so wild in 
their prognostications, as to shoot very wide of 
the mark. Second, are there any such doleful 
predictions hanging over us now? Answer: 
Those who have any claim to be heard on the sub- 
ject must give the Bible as their authority; there- 
fore, the best way to state what is predicted will 
be What do the Scriptures teach? and from this 
we may judge whether what they foretell may 
properly be called "doleful." Take an instance. 
The subject is brought up in Matthew xxix.. 3, 
where the>disciples ask of Christ the direct ques- 
tion. What shall be the sign of the end of the 
world? and the mistake made by expounders is 
in the meaning they give to the word world. It 
is taken to mean the globe on which we dwell, 
hence all the confusion. Whereas its proper use 
is of the world at large ; the course of this world, 
this dispensation, which is to have its end, or, as 
the actual meaning of the Greek is, "the end of 
the age.'" This world is never to end, and the 
Scriptures do not say so ; but on the contrary de- 
