The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1870-12-10
SCIENTIFIC & MECHANICAL

SPONTANEOUS CoMBUsTToS.-A cores
pondent from Bridgeport, Conn, states that
recently in the establishment Of the Win.
! chester Arms Co. a. that place, some riff
ling chips were taken from the draining cans
and thrown in the scrap heap, when, in a
very few moments, they bust into q fierce
flame which required much water to ex-
tinguish. The ri6ing chips mentioned were
fine steel shavings covered with oil.
AN INVENTION WANrED.-An English
contemporary calls attention to the fact that
the ordinary methop Of cleaning door steps,
which requires the operator to kneel on the
cold damp stones, gives rise to a disease
familiar 10 hospital physicians, which it
calls ''housemdids knee" 1t says some
instrument for this purpose, which will not
necessitate kneeling, is an invention much
needed.
A MONSTER gun of IS tuns is being cast
in Woolwich, England. 1t will he riffed
with nine grooves, and the ordinary cart
ridge will contain eighty pounds of powder.
In the manufacture OF sllverware in the
United States, about fifteen hundred work
men arc employed. Abont one million
ounces of silver are annually melted. Add
to this the expenses Of manufacture, and
the amount Of silver-ware annually sold
will be about five millions Of dollars Two
houses in New York sell about one-fourth
of the whole product.
PYRoGRAPHY is a new art invented in
England, and consAts, as the name indi.
Gates, in printing by fire through system
Of metallic cylinders, which burn into the
wood any design required, which is inde-
structible. From its nominal cost and grea.
beauty, it seems likely to take the place Of
much Of the expensive ornamentation and
inlaid work now done by hand
TORPEDO ExPERIM ENrs.-On Tuesday,
Oct. IL, some interesting torpedo expert
ments we're conducted at Chatham, Eng
land, on the occasion Of the visit Of th,
Duke Of Cambridge to that place. The ex
periments began by the explosion of tive
small charges Of gun cotton % shore-on'
by means Of detonatine fuse and the otbe
/ " Cdt-hO ouOW tbot puu COtNOu IN ~
natural state is perfectly harmless, but yer,
destructive when exploded by means of de
tonatio1. The gun cotton which was merel
ignited only made a blaze; that fired b,
detonation made a very sharp report.
torpedo placed 10 the river and filed viii
10 pounds Of gun cotton was then exploded
and even that small charge threw up
large quantity of water. But the che
experiment was with very different tor
pedo in point Of size; it was charged wit
no less than 4S2 pounds Of gun cotto
(Which is considered equal to ! ,296 pound
of gun powder). This powerful iDstrumen
was moored about two hundred ysrls ava
, from the vessel; it was surrounded BY seve
other torpedoss, the object Of the exPer
ment being to ascertain whether the explo
sion Of 20 large q torpedo would lead
: the explosion Of the others Ii was th
opinion Of the officers skilled in such mat
ters that It would not The torpedo wa
J, exploded by an electric current. The etfe'
was grand. Vast volumee Of water vel
cast high into air, and the vessel was mud
shaken, but not one Of the other torpedo
, was exploded Or injured.