1906.] 



Artificial Incubation. 



201 



ARTIFICIAL INCUBATION. 



With the object of securing further data as to the artificial 

 hatching of chickens, the observations made at the Reading 

 College Poultry Farm, Theale, have been continued during the 

 past twelve months. The records of the two previous years 

 were given in the Journal of the Board of Agriculture, June, 

 1904 (p. 135), and May, 1905 (p. 87). For comparison with the 

 present report the complete observations are tabulated in a later 

 paragraph. The work was carried out in the specially built 

 incubator house previously described, and under favourable 

 conditions as to equability of temperature and ventilation. It 

 is, however, necessary to note that the machines are operated 

 by students under the supervision of the practical instructors. 



The conditions under which incubators are worked is an 

 essential factor in the attainment of a successful result. Where 

 several machines are at work the combustion of burning lamps 

 affects the atmosphere to a very large degree, not only drying 

 the air, but exhausting the oxygen which is essential to the 

 growing embryos. Unless, therefore, provision is made for a 

 regular and sufficient supply of pure air, not only will the lamps 

 burn badly, but the hatching results will be adversely affected. 

 As we have had fourteen lamps burning, and nearly 1,800 

 ■eggs undergoing the process of incubation at one time, the 

 importance of fresh air is manifest. In addition, the changes 

 of temperature must be taken into account. No incubator can 

 automatically provide for excessive variations. By minimizing 

 these the strain upon the regulating apparatus is greatly re- 

 duced, and the atmospheric influences in the egg chambers are 

 favourable. Rapid rise or fall in excess cannot fail to cause undue 

 or insufficient heat. Even the most perfect regulator can only 

 work within its limitations. Diagram I. shows these variations 

 both in temperature and humidity, from which it is apparent, as 

 proved in the previous years, that in this country a well built 

 and ventilated incubator house, above ground and favourably 

 situated, will minimize extremes both of heat and cold, while 

 the atmosphere will contain a sufficient supply of moisture. It 

 is interesting to note the evenness of the temperature in the 

 incubator room. On one occasion a maximum of 83 deg. F. 

 was registered — 4 deg. F. above the highest point of the previous 



