CHAP. IV. 



ARTIFICIAL INCUBATION. 



627 



Fig. 180. Egg-tester. 



again, except so far as we have indicated, until the nineteenth day, 

 Tvhen.they can be further examined, but in a different way. Get a pail 

 and nearly fill it with water heated to 103^ F., into which the eggs 

 are to be put. Those which contain live chicks will float on the top, 

 and soon begin to dance about 

 in the water in a peculiar manner, 

 the movements being caused by 

 the efforts of the inmate to get 

 out of its prison, and the vigour 

 of the same largely representing 

 the strength of the chick. Those 

 eggs which sink or do not move 

 at all (be sure of this latter) may 

 be regarded as dead. After al- 

 lowing the others to remain in 

 the water about ten minutes they 

 should be returned, wet as they 

 are, to the nest, and if the eggs 

 have been fresh, some may be 

 expected to hatch out, or at any 

 rate to be chipped, by the next 

 feeding time. The advantage of the water test is that " live " eggs 

 do not become crowded by dead ones, whilst the water undoubtedly 

 softens the shell and makes more easy the escape of the little prisoner. 

 The question of artificial incubation has fascinated many minds. 

 The stories of the egg ovens of China and Egypt are too well known to 

 require recapitulation, and many have been 

 the attempts to provide a machine which 

 would dispense with the services of the hen. 

 Some were excellent, others were either too 

 elaborate or too cumbersome ; but within 

 the last dozen years or so there have been 

 introduced several appliances which are at 

 once reliable and inexpensive. At first sight 

 the work of hatching by artificial means ap- 

 pears so simple, that it is small wonder 

 many methods have been introduced. But 

 it took a long series of years, and involved 

 many failures, before the difficulties in the 

 way of securing regular temperature, fresh 



air, and moisture were solved. A machine cannot think it is unlike 

 the hen in that it has no instinct, and thus every difficulty has to be 

 provided, for, every need anticipated. But if we get a perfect machine 

 it will go like clockwork. The point to be asked is, are incubators of 

 any practical value ? To this we should unhesitatingly answer, Yes, 

 where there is a sufficient number of eggs hatched to justify the cost. 

 An incubator for fifty eggs can do the work of four hens at one 

 time ; but if we consider that it is ready to act all the year 

 round, without any cessation, it is equal to at least sixty hens. 



s s 2 



Fig. 181. Hearson s 

 Incubator. 



