152 



A MANUAL OK KORESTRY 



be of great service and should be kept at vantage points in the 

 forest where it is easily obtainable in case of fire. 



The best tools to IK- kept for such purposes are: long-handled 

 shovels, rakes, axes, mattocks, brooms, pails, and spray pumps. 

 Chemical fire extinguishers are also of great value for surface 

 and it is a much-discussed question whether such extin- 

 guishers or spray pumps are more efficient in extinguishing forest 

 fires. The chemical extinguishers employed for this purpose are 



By permission of the Connecticut State Forester. 



Fig. 56. The fire wardens of a Connecticut town and their fire fighting outfit of bucket 

 pumps. They have been burning over a fire line adjacent to the railroad track. 



fairly light, portable ones, weighing about thirty-seven pounds 

 when charged, and provided with a short hose and nozzle. 

 Various makes of extinguishers are on the market but all based 

 on the same principle. Briefly, the extinguisher contains in the 

 top a small bottle of sulphuric acid, while beneath is a mixture 

 of water and bicarbonate of soda. In working the extinguisher 

 it is inverted and the sulphuric acid mixes with the liquid, result- 

 ing in the formation of carbonic acid gas and calcium sulphate. 

 The chemical reaction forces out through the hose a mixture of 

 water and carbonic acid gas, which, theoretically, stops combus- 



