1917] 



ANIMAL PRODUCTION". 



771 



toward the front of the machine, the bulb on a level with the top of the eggs 

 but not touching them. The touching thermometers were two in number, one 

 on brown and one on white eggs, near the standing thermometer. The bulbs 

 of these were on a level with the top of the eggs and touching them. The Inovo 

 thermometer, which is supposed to register the temperature of the germ in an 

 egg, was placed near the other thermometers. 



Four experiments were made with each incubator, one in 1913, one in 1915, 

 and two in 1916. Brown and white eggs from White Plymouth Rock and 

 White Leghorn pullets, respectively, were used. Except in the first experi- 

 ments the eggs were so selected as to eliminate all possible influences on the 

 hatch by some particular hen or because of the age of the eggs. The machines 

 were run at the following temperatures as registered by the standing ther- 

 mometer during the first, second, and third weeks : Machine No. 1, 100, 101, 

 102° F. ; machine No. 2, 101, 102, 103° ; machine No. 3, 102, 103, 104° ; and ma- 

 chine No. 4, 103, 104, 105°. The following table gives some of the results 

 obtained : 



Results of incubation experiments tcith white and brown eggs. 



No reason from the standpoint of incubation was found for the poor showing 

 of the brown eggs as compared with the white eggs. It was found brown and 

 white eggs need the same temperature. Machine No. 1 produced 69.3 per cent 

 of vigorous chicks to fertile eggs ; machine No. 2, 69.5 per cent ; machine No. 3, 

 64.4 per cent ; and machine No. 4, 30.5 per cent. In every test machine No. 2 

 produced the largest, plumpest, and best chicks. The chicks in machines Nos. 1 

 and 3 were very similar, but those in No. 4 were poor and weak in every hatch. 



The average weekly temperatures for the four experiments as recorded by the 

 different thermometers in incubator No. 2, with which the best hatches were 

 obtained, were as follows: 



Average temperatures in machine No. 2. 



It is stated that the incubator records show that the temperatures were held 

 practically to the desired point daily. 

 94087°— No. 8—17 6 



