428 ENGINEERING ON THE FARM 



rate of about >2 foot per hour, whereas about 3 feet of the 

 ordinary city gas must be consumed to produce an equal 

 intensity of light. If burned with a mantle, the city gas 

 would produce about the same quality of light as the acety- 

 lene gas. 



The acetylene plant is decidedly the most delicate of any 

 of the plants so far considered. (See Figs. 326 and 327.) 

 It involves a machine in which carbide may be placed. To 

 meet the underwriters' specifications, this carbide must be 

 allowed to drop into a chamber partly filled with water. 

 In no case should the water be allowed to fall upon the 

 carbide. Another detail of the plant is a holder or retainer 

 for the gas which has been produced in the water chamber. 

 This holder must be provided with a float, or otherwise bal- 

 anced mechanism, which will set in motion the mechanism 

 which allows the carbide to drop into the water. 



This is the essential feature of an acetylene machine, for 

 upon the precision with which this device controls the 

 production of gas depends the safety of the machine from 

 leakage of gas. This escaping gas is very likely to be 

 exposed to flame and an explosion result. 



A plant of this kind must be installed where there is no 

 danger of freezing, and where there is no raw flame at any 

 time exposed to the atmosphere around the plant; that is, 

 it must be installed where the temperature is never below 

 freezing; or, if the premises must be heated, the steam or 

 hot-water plant must be placed at some distance from the 

 acetylene apparatus. 



We frequently read of the explosion of acetylene gas plants. 

 It is very hard to get actual facts concerning one of these 

 accidents, but it is only conservative to say that the explo- 

 sions are due to carelessness in the manipulation or care of 

 the plant; for example, when the plant has been allowed to 

 run down and an attendant approaches after dark with a 

 lantern, or when the quite delicate apparatus necessary for 

 the control of the carbide-feed may have become corroded 



