﻿Acetylene. 95 



lump of carbide, ignite the gas and show that the more 

 water is poured on, the more flame is obtained. Various 

 forms of generators can be used for the gas. The simplest 

 one is a bell glass lloatincp on water and containing a few 

 lumps of carbide in a sieve. As soon as the bell glass 

 descends so that the sieve touches the water, a shower of 

 fine sediment of slaked lime can be seen to separate from 

 the carbide and fall to the bottom of the jar, while the 

 gas generated soon causes the bell to rise and removes 

 the carbide from contact with the water. Thus the appa- 

 ratus can be made to work automatically, generating gas 

 only as fast as it is used; but it is not fitted for permanent 

 use, because the moisture from the water generates gas, 

 even when the contact has ceased, and the bell gradually 

 rises, so that after twenty-four hours gas would escape if 

 it were not used during the interval. 



It is in every way preferable to separate the generator 

 and the gas holder, and such arrangements can easily be 

 made automatic. 



The acetylene company has patented a tank for generat- 

 ing the gas under sufficient pressure to liquefy itself, and 

 proposes to distribute liquid acetylene in cylinders under 

 a pressure of 600 to 700 pounds to the inch ; of this pro- 

 ject more is to be said later. 



It is certain that a company purchasing the carbide of 

 calcium and using an existing gas plant could generate 

 acetylene and distribute it through mains at a very small 

 expense, and with little skilled labour, so that when a 

 price for the carbide had l^een established by contract the 

 cost of the gas could be easily estimated ; let us see what 

 price such a company could expect to obtain from a con- 

 sumer. 



Value of Acetylene as an Illuminant. 



Suppose we take the case of a competition with the 

 gas companies of a large town. At first sight it would 



