Anticipating
what will be said later, in cases like these, the cost of lighting by
self-luminous acetylene may fairly be compared with self-luminous coal-
gas or oil only; although in other positions the economy of the Welsbach
mantle must be borne in mind.
Acetylene lighting presents also certain important hygienic advantages
over other forms of flame lighting, in that it exhausts, vitiates, and
heats the air of a room to a less degree, for a given yield of light,
than do either coal-gas, oils, or candles. This point in favour of
acetylene is referred to here only in general terms; the evidence on
which the foregoing statement is based will be recorded in a tabular
comparison of the cost and qualities of different illuminants. Exhaustion
of the air means, in this connexion, depletion of the oxygen normally
present in it. One volume of acetylene requires 2-1/2 volumes of oxygen
for its complete combustion, and since 21 volumes of oxygen are
associated in atmospheric air with 79 volumes of inert gases--chiefly
nitrogen--which do not actively participate in combustion, it follows
that about 11.90 volumes of air are wholly exhausted, or deprived of
oxygen, in the course of the combustion of one volume of acetylene.
Pages:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25