30 
THE YOUNG SCIENTIST. 
out from tte socket, wash, aud dost with the alum 
mixture, theu fill with, cotton. 
Next, wash the neck carefully, and cover with the 
powder ; then make a frame of wire which must 
<2onsist of a large circle — of size of the large end of 
the neck, and a very small one fitting in the narrow 
part next the head, uniting them with four straight 
pieces, that will keep the neck extended ; then cover 
with muslin wound round each wire, and putting the 
frame in the open skin, fill the whole cavity with tow 
or cotton. Next put in the eyes, consisting of beads 
or, far prettier, the regular glass eyes sold by taxider- 
mists and fancy stock dealers. If not too large, 
these are easily inserted after removing the ball of 
cotton, and the juices from the lid will form a cement 
that will hold them. Thus mounted, your head will 
dry out without any trouble, but if the weather is 
warm, use corrosive sublimate, instead of alum and 
a,rsenic. 
Next cut a piece of pasteboard fifteen inches long 
<more or less), which cover neatly with colored mus- 
lin. Around the edge sew a border of handsome 
peacock's or cock-tail feathers, and a row of each is 
very beautiful, then place the cock's head in place, 
and in the centre of the back arrange several grace- 
ful waving plumes. By lifting the outer row of 
feathers, the stitches are easily inserted. 
Wash the feet very clean, rub the raw end with 
the alum and arsenic, score the under part of each 
claw and rub in all the arsenic and alum possible, 
then sew up the skin ; varnish (when quite dry) 
with dammar, and fasten as shown in the illustra- 
■tion. 
The Water Hammer. 
This is a very curious little piece of apparatus, 
which any boy can easily make for himself Take a 
piece of glass tubing with pretty thick sides ; the 
bore should be about one-fourth of an inch, and the 
outside diameter about three-eighths of an inch. Heat 
the end strongly in a spirit lamp or Bunsen burner, 
Th« latter will answer without a blow-pipe and even a 
good spirit lamp with an organd or circular wick will 
.answer. The end of the tube being soft, draw it 
away, and the glass will gradually close. It must 
now be thickened by heating it strongly in the flame, 
rotating it constantly, and pressing the glass care- 
fully up with a piece of metal. When the glass is 
thick enough, bring it to a bright cherry red, remove 
it from the flame and blow into it, rotating it all the 
while. It will soon look like A. Now heat it about 
six inches from the ball, and draw it out as shown 
in B, until the bore is not larger than a pin. Cool it 
very gradually, and when quite cold fill it two- 
thirds full of water. If you have some rubber tub- 
ing and a spring clip as shown at B, they are the 
most convenient for the next step. But a good sound 
cork will answer. Or if you have the rubber tube 
and no clip, put on the rubber, and in it put a piece 
❖f glass or metal rod about one-sixteenth of an inch 
less in diameter than the bore of the tube. Now 
grasp the tube, just below the rubber tube, with a 
common wooden spring clothespin, and hold it over 
a small spirit lamp until one-third of the water haa 
boiled away in steam — passing out between the rub- 
ber tubing and the glass or metal rod. Let an assist- 
ant now tie a fine but strong cord firmly around the 
rubber tube, and it will be pressed against the inner 
rod so that it will be closed air tight, and remember 
that at the very instant that the cord is drawn tight, 
the lamp must be removed or more steam will be 
made, and you may have a boiler explosion on a 
small scale. By applying a sharp jet of flame to the 
.\ B C 
The Water Hammer. 
thin part of the tube it may now be sealed up air 
tight, or hermetically as it is called, and the water 
hammer is finished, looking like C, but not quite so 
dumpy. 
If you have done everything properly, the tube and 
ball will now be empty of every thing except a little 
watery vapor — all the air having been driven out by 
the steam from the boiling water. If the bulb is 
shaken, the water meets with no resistance in its 
movements and makes no froth or bubbles. But the 
strange point is that when the water is thrown 
quickly from one end to the other, it strikes the glass 
like a hammer, and gives a sharp metallic ring. 
Hence the name. Under ordinary circumstances, 
when water is driven against a hard body, the air 
forms a cushion, and a slushing sound is heard. 
Here however, the cushion is absent, and the water 
comes at once in contact with the glass, in which it 
produces the same vibrations that a solid body would 
make. These vibrations pass from the glass to the 
air outside, and thence to our ears. 
A Seasonable Experiment. 
It has been found that the temperature at which 
water freezes depends upon the pressure to which it 
is subjected, and a block of ordinary ice, if subjected 
to suflBcient pressure, might be entirely melted. 
The following very striking experiment which illua- 
