212 POULTRY PRODUCTION 



Table XXV. — Effect op no Moisture, Medium Moisture, and 

 Maximum Moisture. 



In this case the relative humidity averaged 48.7 per cent, 

 in the non-moisture machines, 55.3 per cent, in the medium 

 moisture, and 64.7 per cent, in the machines having the 

 maximum supply of moisture. The corresponding wet-bulb 

 temperatures were 84.5°, 87.6°, and 91°. At the same time 

 the relative humidity of the room where the incubators 

 were operated ranged from 66 per cent, to 83.1 per cent., 

 with an average of 73.4 per cent. 



In other observations made in Utah, where it was 

 much drier and the relative humidity of the room where 

 the incubators were operated was only 45.5 per cent, on 

 the average, Dryden^ found that the maximum moisture 

 machines had a relative humidity of but 55.5 per cent, and 

 gave the best results. 



Referring to the Oregon results, Dryden says: "In com- 

 paring the weighings of incubator and hen eggs, the eggs 

 in the non-moisture incubators lost 12 per cent, more weight 

 than the eggs under hens, but the moisture machine showed 

 less loss. The results show that the dry machines "dry 

 down" the eggs too much, while the maximum moisture 

 machines show too little evaporation. Between the medium 

 moisture machines and the hens there is considerable differ- 

 ence. It is a question, however, if less evaporation of the 

 eggs under the hens would not be desirable. It has never 

 been demonstrated, to the writer's knowledge, whether it 

 is better to set the hens on the ground than on dry nests. 

 On the whole the result of the weighings agrees with the 

 results of the hatching in showing the necessity of supplying 

 a certain amount of moisture to the incubator." 



Best Means of Supplying Moisture. — Dryden^ found that 

 a tray of moist sand placed in the bottom of the nursery 



' Oregon Bulletin No. 100. '- Utah Bulletin No. 102. 



