30 THE YOUNG 
sporting dog gave a snap of 72 pounds at the 
muzzle, corresponding to a contractile force in 
the muscle of 360 pounds. 
— Ordinary vulcanized caoutchouc should con- 
tain about 1-10 to 1-6 of sulphur, a greater propor- 
tion yielding a hard, horn-like product. which ex- 
pands considerably when heated. It was estab- 
lished by Mr. Kohlrausch, some years ago, that 
this hard caoutchouc, while expanding equally 
with mercury up to the freezing point, expands 
much more at higher temperatures ; so that in a 
thermometer consisting of a vessel of this mate- 
rial filled with mercury, the latterwould appear to 
contract with an increase of temperature. Ee- 
sults of experiments made by Mr. R. Fuess, of 
Berlin, appear to confirm Professor Kohlrausch's 
statement. Mr. Fuess placed a rod of caoutchouc, 
1-5 inch thick, in a glass tube, 3-5 inch diameter, 
and filled the tube with mercury to a height of 3 
feet, exactly up to a little pin of platinum project- 
ing horizonitally from the caoutchouc. The cal- 
culations from fifteen observations, in which he 
was assisted by Dr. M. Tiessen, gave an expan- 
sion co-efficient of .000082 for each degree C. up to 
a temperature of 65° F. ; higher figures resulting 
from observations at higher temperatures. 
Ciirveiit llotrs. 
— A medical man, struck with the large number 
of boys under fifteen years of age he observed 
smoking, was led to inquire into the effect the 
habit had upon the general health. He took for 
his purpose thirty-eight, aged from nine to fif- 
teen, and carefully examined them. In twenty- 
seven he discovered injurious traces of the habit; 
in twenty-two there were various disorders of 
the circulation and digestion, palpitation of the 
heart, and' a more or less taste for strong drink. 
In twelve there were frequent bleedings of the 
nose, ten had disturbed sleep, and twelve had 
slight ulceration of the mucous membrane of the 
mouth, which disappeared on ceasing the use 
of tobacco for some days. 
— Without doubt the largest kite in the world 
Avas lately made by Dr. Beebee, near Rochester, 
N. Y. According to the Rochester Express, the 
frame was made of lumber 2 inches wide by Yz 
inch thick, and was covered with manilla paper. 
The surface contained nearly 250 sqdare feet. 
The string by which the kite was flown was a coil 
of ?8-inchrope, ordered from Rochester, and was 
nearly 5,000 feet in length. To the astonishment 
of hundreds of spectators, it shot into the air like 
a balloon. After the monster had floated a mile 
high for a couple of hours the problem of getting 
it down was next in order, and was not accom- 
plished until a pulley and team was brought and 
liiiuled it down. 
— Among the newest Christmas cards are tablets 
of ivory upon which mottos and quaint pictures 
are painted. A tiny scent bottle not more than 
SCIENTIST. 
an inch and a half in length, is "a novelty. It is 
made half of thick glass and half of silver; the 
silver portion screws on over a small glass 
stopper. It is intended to slip in the inside of 
the glove, and is made very smooth for thut pur- 
pose. A heavy piled plush is stamped with a 
pug's head. It is in a shade corresponding to the 
background, so that the dog's head, which is 
clearly deflned, seems to be peeping out of a soft 
warm nest. Many ladies suffering from the an- 
tique fever are dipping their costy laces in coffee 
to give the desired " yellowed with age " look. 
— Mr. Dardenne's self-winding clock may be 
considered to have had a fair trial. A specimen 
clock was fixed at the Gare du Nord terminus, 
Brussels, last September, due precaution being 
taken to avoid tampering with it by affixing 
the Government seal. After six months' trial it 
was found in perfect time with the Observatory 
clock. The clock is wound by a small anemome- 
ter or windmill, which is, by a reversed train of 
multiplying wheels, continually drawing over 
each wheel an endless chain, in one loop of which 
the clock weight is supported. As the loop hangs 
between the clock and the winding machine, the 
weight is continually drawing through the clock 
the slack chain drawn up by the wind motor, 
and thus a constant motion is maintained. A 
ratchet wheel prevents the motion from turning 
the wrong way, and whenever the weight is 
wound right up to the top the motion is checked 
by a friction brake automatically applied to the 
anemometer by the raised weight lifting a lever. 
When the weight is fully raised the clock has a 
sufficient store of energy to go for twenty-four 
hours. 
— Dr. Franklin invented a stove in 1745. Pre- 
vious to that time there were stoves in Holland 
and Germany. Franklin's stove, however, was a 
great improvement on all that had preceded it. 
In 1771 he invented several other stoves, one for 
burning bituminous coal, which would consume 
its own smoke and had a downward draught, and 
another intended for the same purpose, having a 
basket grate or cage, with movable bars at the 
top and bottom, supportedby pivots at the centre, 
and which, after being filled and kindled at the 
top, could be inverted, and so made to burn from 
the base. The next inventor of stoves, ovens, 
and heating and cooking apparatus, was Count 
Rumford, who, between 1785 and 1795, devised 
several improvements, all intended to economize 
fuel and heat. It may be stated that the box 
stove now in the State House at Richmond, Vir- 
ginia, bears date of 1770, is one of the so-called 
Holland stoves, and was probably imported from 
England, as the castings, though rude, are 
superior to the American castings of that day. 
For cooking purposes Count Rumford's cooking 
stoves or ranges, lined with fire-brick or soap- 
stone, and with a ventilating oven, which had 
been introduced into New York as early as 1798, 
and into Boston about 1800, were gradually com- 
ing into lase, and between that time and 1825 there 
