1905.] 



Artificial Incubation. 



89 



the remarkable evenness of the incubator room, in spite of 

 variations in the outer atmosphere. The lowest record is on 

 January 16th, 1905, Morning 40 0 F., Afternoon 42 0 F., when the 

 outer registers were, maximum 35 0 F. and 25 0 F., respectively. 

 On. the 2nd of that month, when the thermometer outside fell to 

 i8 Q F., the room was not below 45 0 F. On the other hand, on 

 June 27th, 1904, when the maximum outside temperature 

 reached 85 0 F., the incubator room did not rise above 67° F. 

 The highest record was on August 29th, 1904, namely, 79 0 F. 



Interior of Incubator House. 



Such results could only be obtained in an above-ground building, 

 if it is sheltered from the sun's rays and well ventilated. The 

 incubator house at Theale is effectively shaded by a large 

 walnut tree. The humidity records show that whilst at no part 

 of the year was saturation point reached in the incubator room, 

 only on three occasions out of the selected days did the atmos- 

 pheric moisture exceed 90 per cent., and that only on four of 

 these days did it fall below 70 per cent. The variations of 

 temperature and humidity in the incubator room are shown in 

 Diagram I., from which it is apparent that the dampness or 



