i9o6.] 



Artificial Incubation. 



203 



directions for explanation of these differences. A wet and dry 

 bulb hygrometer is used, by which the temperature of the 

 room is recorded, with the saturation point (100 deg.) ; and the 

 humidity is calculated by means of Glaisher's hygrometrical 

 tables. 



In the two previous years three leading makes of incubators 

 were used, but this year three others have been added, so that 

 the observations are in that respect more complete. Those 

 operated were as follows : — A, Hearson's Champion ; B, 

 Tamlin's Nonpareil ; C, Cypher's Standard ; D, Tamlin's 

 Imperial ; E, Chas. Cypher's Model ; and F, Draper's J.M.D, 

 Of these A, B, and F are tank machines, C, D, and E are 

 on the hot-air, non-moisture principle. These three latter, 

 although differing in minor details, are practically of the same 

 type. But in respect to the C form, we have used this year 

 a larger size than previously, namely, one holding 360 eggs, 

 and, as is seen in Table I., the results have been most satis- 

 factory, giving a percentage of 76*52, which is above the general 

 average. These incubators were not, however, filled to the 

 extent of their capacity. Table I. gives the record of each 

 hatching in the entire twelve months, showing (i) number of 

 eggs placed in the machine, (2) number of fertile eggs as 

 revealed by testing on the seventh day, (3) number of chickens 

 hatched, and (4) percentage of fertile eggs hatched. 



During the twelve months under review the number of 

 hatchings was 89, or 21 more than in the previous year. Into 

 the machines were placed 7,790 eggs ; of these 6,330 proved 

 to be fertile, a percentage of 81*13, so that the fertility was 

 0*98 per cent, higher than in 1904-5 ; the chickens and 



TABLE I.— HATCHING RECORDS, 



Date of Hatching. 



Class of 

 Machine. 



No. of Eggs. 



No. of Fer- 

 tile Eggs, 

 7th day. 



No. of 



Chickens 

 Hatched. 



Fertile Eggs 

 Hatched. 



1905. 











Percentage. 



April 3 



C 



lU 



94 



56 



59-57 



3 



A 



95 



72 



59 



81-94 



3 



C 



90 



79 



64 



75-95 



5 



A 



62 



54 



46 



85-18 



„ 12 



B 



53 



40 



33 



82-5 



„ 14 



C 



225 



208 



167 



?0-29 



„ 17 



A 



48 



42 



33 



78-57 



„ 17 



C 



110 



85 



57 



67-06 



„ 28 



C 



122 



96 



81 



84-37 



„ 26 



B 



98 



84 



71 



84-52 



„ 26 



A 



98 



89 



70 



78-65 



„ 28 



A 



50 



42 



37 



88-1 



