2. Under the same conditions as to firedamp, a charge of roburite was
placed on a block of wood inside the boiler, totally unconfined except
by a thin covering of coal dust. When exploded by electricity, as in
the previous case, no flame was produced, nor was the firedamp
ignited.

3. The preceding experiment was repeated with the same results.

4. A charge of blasting gelatine, inserted in one of Settle's water
cartridges, was suspended in the boiler tube and fired with a
fulminate of mercury detonator in the usual manner. The gelatine did
not, however, explode, the only report being that of the detonator.
After a safe interval the unexploded cartridge was recovered, or so
much of it as had not been scattered by the detonator, and the
gelatine was found to be frozen. This fact was also evident from an
inspection of other gelatine dynamite cartridges which had been stored
in the same magazine during the night. This result, although not that
intended, was most instructive as regards the danger of using
explosives which are liable to freeze at such a moderate temperature,
and the thawing of which is undoubtedly attended with great risk
unless most carefully performed. Also, the small pieces of the
gelatine or dynamite, when scattered by the explosion of the
detonator, might cause serious accident if trodden upon.--_Engineering._

* * * * *

THE MECHANICAL REELING OF SILK.

When automatic machinery for thread spinning was invented, English
intelligence and enterprise were quick to utilize and develop it, and
thus gained that supremacy in textile manufacture which has remained
up to the present time, and which will doubtless long continue. The
making of the primary thread is the foundation of all textile
processes, and it is on the possibility of doing this by automatic
machinery that England's great textile industries depend. The use of
highly developed machinery for spinning cotton, wool, and flax has
grown to be so much a part of our conception of modern life, as
contrasted with the times of our grandfathers, as often to lead to the
feeling that a complete and universal change has occurred in all the
textile industries. This is, however, not the case. There is one great
textile industry--one of the most staple and valuable--still in the
primitive condition of former times, and employing processes and
apparatus essentially the same as those known and employed before such
dev