The superiority of a chemical engine consists--

1st. In its simplicity. It dispenses with complex machinery, experienced

engineers, reservoirs, and steam. Carbonic acid gas is both the working

and extinguishing agent.

2d. In promptness. It is always ready. No steam to be raised, no fire to

be kindled, no hose to be laid, and no large company to be mustered. The

chemicals are kept in place, and the gas generated the instant wanted.

In half the cases the time thus saved is a building saved. Five minutes

at the right time are worth five hours a little later.

3d. In efficiency. Mere water inadequately applied feeds the fire, but

carbonic acid gas never. Bulk for bulk, it is forty times as effective

as water, the seventy gallons of the two smallest cylinders being equal

to twenty-eight hundred gallons of water. Besides, it uses the only

agent that will extinguish burning tar, oil, and other combustible

fluids and vapors. One cylinder can be recharged while the other is

working, thus keeping up a continuous stream.

4th. In convenience. Five or six men can draw it and manage it. Its

small dimensions require but small area, either for work or storage. One

hundred feet or more of its light, pliant hose can be carried on a man's

arm up any number of stairs inside a building, or, if fire forbids, up a

ladder outside.

5th. In saving from destruction by water what the fire has spared.

It smothers, but does not deluge; the modicum of water used to give

momentum to the gas is soon evaporated by the heat, doing little or no

damage to what is below. This feature of the engine is of incalculable

worth to housekeepers, merchants, and insurance companies.

6th. Economy. It costs only about half as much as a first class hand

engine, and about one-fourth as much as a steam engine, with their

necessary appendages, and the chemicals for each charge cost less than

two dollars.

* * * * *

Scientific American Supplement, No. 358, November 11, 1882 · 第 19 / 50 题