THE YOUNG 
SCIENTIST. 
116. To f^ild ou filass. first clean and dry the 
glass thoroughly, then lay out the lines for let- 
ters with a piece of hard scented soap, then paint 
the letters on the right side of the glass with lamp- 
black mixed with oil, in order to form a guide for 
the work, then on the inside lay on a coat of size, 
using a camel's-hair brush, covering the whole 
of the letters ; next lay on the gold leaf with a 
tip, until even^ part of the letters is covered well. 
Let the leaf remain until the size is dry. when 
you will find that the letters on the front side can 
be easily seen and traced. This is done with 
quick drying black, mixed with a little varnish. 
Paint over the whole directly over the gold ; allow 
it to dry; then wipe off with soap and water the 
lampblack letters from the front side ; with pure 
cold water and a clean sponge, wash the super- 
fluous gold leaf and size from the back, and you 
will have a splendid gold letter on the glass; 
next, shade your letter to suit the taste, always 
remembering to shade to the edge of the gold, for 
then you have only one edge to make straight. 
The other edge may be left rough, and when dry 
may be straightened by scraping with a knife. 
In making scrolls, eagles, etc., on glass, some 
painters put on the outlines and shades first, and 
then lay the gold leaf over all ; another good way 
is to scratch the shades on to the gold leaf after it 
is dry. and put the colors on the back of the gold. 
Silver leaf may be used in the same manner as 
gold, but it will not wear as well. A very pretty 
letter may be made by incorporating silver with 
gold: take paper and cut any fancy design to fit 
the parts of the letter; stick it on the size before 
laying the leaf, allowing it to dry, and wash off as 
before ; then with a penknife raise the paper fig- 
ure, and the exact shape or form of the figure 
will be found cut out of the the gold letter; clean 
off nicely, apply more size, and lay silver leaf to 
cover the vacant spots ; wash off when dry, and a 
very handsome letter will be the result. Colors 
may be used instead of silver, if desired, or a 
silver letter edged or "cut up" with gold, will 
look well.— Snob. 
117. Sadie.— Drop your shells into hot water, 
and gradually increase its temperature to boil- 
ing point. When they are quite dry rub them 
over with a little olive oil. Sea-shells should be 
steeped in water till the salt is extracted. Coral 
is bleached by being boiled in water to which 
oxalic acid has been added. 
118. In strict architectural parlance— yes ; in 
ordinary language— no. The house should be 
larger than the villa, and the villa than the cot- 
tage: but in almost every suburban street where 
the houses are identical in size, plan, and con- 
struction, you will find one man calling his 
<lwelling a " house," his next door neighbor re- 
joicing in a " villa." while his friend to the left is 
satisfied with a, "cottage," and his next-door- 
but-one proclaims itself to be a " residence." 
119. Make a box with the top, bottom and sides 
of thin wood, and the ends inch beech, form it 
the same length as the width of the window in 
which it is to be placed. The box should be three 
or 4 inches deep, and 6 or 7 inches wide. In the 
top of the box, which acts as a sounding board, 
make three circular holes about 2 inches in di- 
ameter, and an equal distance apart. Glue across 
the sounding board, about 2}4 inches from each 
end, two pieces of hard wood M inch thick, and K 
inch high, to serve as bridges. You must now 
procure from any musical instrument maker 
twelve steel pegs similar to those of a pianoforte, 
and twelve small brass pins. Insert them in the 
folIoAving manner into the beech; first commence 
with a brass pin,!then insert a steel peg, and so 
on. placing them alternately H inch apart to the 
numl)er of twelve. Now for the other end, whicli 
you must commence with a steel peg. exactly op- 
posite the brass pin at the other end, then a brnss 
'pin. and so on, alternately to the number of 
"twelve ; by this arrangement you have a steel peg 
and a brass pin always opposite each other, which 
is done so that the pressure of the strings ou the 
instrument shall be uniform. Now string the in- 
strument with twelve first violin strings, making 
a loop at one end of each string, which put over 
the brass pins, and wind the other ends round 
the opposite steel pegs. Tune them in unison, 
but do not draw them tight To increase the cur- 
rent of air, a thin board may be placed about 2 
inches above the strings, supported at each end 
by two pieces of wood. Place the instrument in 
a partly opened window, and to increase the 
draft open the opposite door. See back numbej-s 
of the Young Scientist for further information.— 
Music. 
120. Jumbo.— Is the density of the matter of 
which any body is composed, compared with the 
density of another body assumed as the stand- 
ard, or 1,000. This standard is pure distilled 
water for liquids and solids, and atmospheric air 
for gaseous bodies and vapors. Thus as gold is 
19 and silver ten times heavier than water, those 
numbers, 19 and 10, are said to represent the 
specific gravity of gold and silver. The heaviest 
known substance is iridium, used for pointing 
gold pens ; its specific gravity is 23. The lightest 
of all liquids has a specific gravity of 0.6, it is 
called chimogene, and is made from petroleum ; 
it is exceedingly volatile and combustible, being, 
in fact, a liquefied gas. Carbonic acid gas or 
choke damp is 500 times lighter than water, com- 
mon air 800, street gas about 2,000, and pure hy- 
drogen, the lightest of all substances, 12.000 
times. The heaviest substance has thus 23 -f- 
12,000, or more than a quarter of a million times 
more weight than an equal bulk of the lightest; 
and the substance of which comets consists is 
supposed by astronomers to be even several 
thousand times lighter than hydrogen gas.— 
Kino. 
121. Antiquarian.— The oldest specimen of 
pure glass bearing anything like a date is a 
little moulded lion's head, bearing the name of 
an Egyptian king of the eleventh dynasty, in the 
Slade collection at the British Museum. That is 
to say, at the period which may be moderately 
placed at more than 2,000 years B. C, glass was 
not only made, but made with a skill which shows 
that the art was nothing new. The invention of 
glazing pottery with a film or varnish of glass is 
so old that among the fragments which bear in- 
scriptions of the early Egyptian monarchy are 
heads possibly of the first dynasty. Of later glass 
there are numerous examples, such as a bead 
found at Thebes, which has the name of Queen 
Hatasoo, or Hashep, of the eighteenth dynasty. 
Of the same period are vases and goblets and 
many fragments. It cannot be doubted that the 
story prepared by Pliny, which assigns the credit 
of the invention to the Phoenicians, is so far true 
that these adventiirous merchants brought speci- 
mens to other countries from Egypt. Dr. Schlie- 
mann found disks of glass in the exca.vations at 
Mycenae, though Homer does not mention it as a 
substance known to him. That the modern art 
of the glass-blower was known long before is 
certain from representations among the pictures 
on the walls of a tomb at Beni Hassan, of the 
the twelfth Egyptian dynasty ; but a much older 
picture, which probably represented the same 
manufacture, is among the half -obi iterated 
scenes in a chamber of the tomb of Thy at Sak- 
kara, and dates from the time of the fifth dynasty, 
a time so remote that it is not possible, in spite 
of the assiduous researches of many Egyptolo- 
gers, to give it a date in years.— Keeamic. 
122. — To Katie B.— The writer of the lines you 
quote was Charles Swain.— Philip. 
Queries. 
123. Having a lot of fancy chickens, and wish- 
ing to keep them all winter, I am desirous of 
having a warm house built for the purpose. Do 
you think a house built of gravel or concrete 
would be warm enough? and if so, could vou 
give me a few hints regarding the materials to be 
