temperatures of the wet thermometer and the dry 

 one. If moisture affects a small amount of mer- 

 cury that much, what will it do with from twenty 

 to forty times the bulk? Iron and steel are too 

 slow to contract, or return. Gold and silver are 

 too expensive, and are not equal to brass as a 

 metal part. Remember that there are many kinds 

 of brass, and all kinds will not answer. Liquids 

 are not safe ; besides the danger of a leak, the 

 expansion and contraction of the metal in which 

 they are confined must be overcome or compen- 

 sated for. 



MOISTURE GAUGES AND HYGROMETERS. 



We have experimented with many moisture 

 gauges and hygrometers both inside and outside 

 of incubators, and have not found them of any 

 practical use inside of an incubator. The majority 

 of those offered to poultrymen are not at all 

 117 



