The Chemistry of Powder and Explosives - Sciencemadness Dot Org

JAPANESE TORPEDOES 107
minate but without effect upon objects which are even a few
inches away.
In one plant which the present writer has visited, the fulminate
destined to be loaded into the torpedoes rests in a small heap in
the center of a piece of thin rubber (dentist's dam) stretched
over a ring of metal which is attached to a piece of metal weighing
about a pound. This is held in the worker's left hand, and a
scoop made from a quill, held in the right hand, is used to take
up the fulminate which goes into each torpedo. If the fulminate
explodes, it destroys the piece of stretched rubber—nothing else.
And the rubber, moreover, cushions it so that it is less likely to
explode anyway. The pound of metal is something which the
worker can hold much more steadily than the light-weight ring
with its rubber and fulminate, and it has inertia enough so that
it is not jarred from his hand if an explosion occurs. After the
fulminate has been introduced into the paper cups, the edges of
each cup are gathered together with one hand and twisted with
the thumb and forefinger of the other hand which have been
moistened with paste. This operation requires care, for the torpedo
is likely to explode in the fingers if it is twisted too tightly.
Torpedoes, whether silver, Japanese, or globe, ought to be
packed in sawdust for storage and shipment, and they ought not
to be stored in the same magazine or shipped in the same package
with other fireworks. If a number of them arc standing
together, the explosion of one of them for any reason is practically
certain to explode the others. Unpacked torpedoes ought
not to be allowed to accumulate in the building in which they
are made.
Japanese Torpedoes
The so-called Japanese torpedoes appear to be an American
invention. They contain a paper cap placed between two masses
of gravel, and in general require to be thrown somewhat harder
than silver torpedoes to make them explode. The same torpedo
board is used as in the manufacture of silver torpedoes, but a
gravel board which holds only about half as much gravel. After the
gravel has been put in the paper cups, a paper cap, still moist,
is placed on top of it, more gravel, substantially equal in amount
to that already in the cup, is added to each, and the tops are
twisted.