Rose, Downs & Thompson Hull. Our drawing explains itself. It will be
seen that we have here a swiveling crane and grab bucket, and that the
stuff dredged can be loaded into the barge and conveyed where necessary.
The lifting power of the crane is one ton, and in suitable material such
a dredger can get through a great deal of work in a comparatively short
time.--_Engineer_.

[Illustration: IMPROVED ONE-TON BUCKET DREDGER.]

* * * * *




HISTORY OF THE FIRE EXTINGUISHER.


The first fire extinguishers were of the "annihilator" pattern, so
arranged in a building that when a fire occurred carbonic acid gas was
evolved, and, if the conditions were right (as the mediums say), the
fire was put out. It worked very nicely at experimental fires built
for the purpose, but was apt to fail in case of an involuntary
conflagration. About the year 1867 a patent was granted to Carlier
and Vignon, of France, for an apparatus in which water saturated with
carbonic acid gas was projected upon the fire by the expansive force of
the gas itself. As the apparatus was portable and the stream could be
directed to any point, it was obviously the desideratum needed. Mr. D.
Miles, of Boston, purchased the American patent, and subsequently sold
the territory, exclusive of New England, to the Babcock Co., who, at the
time, had a crude apparatus of their own. The first machines sold under