88 



THE BOOK OF POULTRY. 



even more, hours in getting out. They can, how- 

 ever, be " assisted " with more average success 

 than with chicks. It is remarkable that Ameri- 

 can experience also differs in this respect, strong 

 duck eggs coming out as a rule more quickly 

 than with us, so that here again we have to 

 " level up " to trans-Atlantic practice. 



Turkey and goose eggs are also generally 

 thought to hatch better with a little lower tem- 

 perature than hen eggs ; but experience in 

 hatching either has hardly been sufficient to 

 settle the point with certainty. Experimentally, 

 both have hatched with entire success ; but it is 

 not so easy to rear poults artificially as with a 

 mother, and goose-breeding also appears to 

 "work" best in the natural way. It is curious 

 that ostrich eggs are hatched in incubators far 

 more largely than either. Hydro-incubators 

 were very early used for this purpose it the 

 Cape, but have since been superseded by 

 modern British machines built specially for the 

 purpose. The Phcenix Ostrich Farm in Ari- 

 zona, and the Florida Ostrich Farm at Jackson- 

 ville, in the latter State, use an American 

 machine ; and, with the aid of incubators, 

 ostrich culture seems extending. 



It does not answer to hatch together eggs 

 too different in size. One reason is that the 

 smaller egg not only holds less heat in itself, 

 but has more evaporating surface in propor- 

 tion, and therefore dries out the air-cell at a 

 different rate. In many machines, especially of 

 the Hearson cool-bottom construction, the tem- 

 perature of the top side of the large eggs would 

 be one or two degrees higher than of the small 

 ones, and this also would impair results. 



When a hatch is complete, it is well to open, 

 air, and if necessary, disinfect the machine. 

 Thij may need it, owing to dead germs having 

 been left in too long, and occasioning a musty 

 smell. Where moisture trays have been used, 

 they should be scalded with boiling water, and 

 any earth or sand used in the egg drawers well 

 baked, to kill any bacteria which may have been 

 introduced. The trouble of doing this comes 

 but seldom, and is very little ; it often percep- 

 tilby affects the next hatch. When a machine 

 is discarded for the season, if it has a tank, 

 this should be quite emptied, and the whole ot 

 the interior carefully wiped and cleansed out. 

 Hot-air flues and radiating chambers should 

 likewise be cleared from soot, which is more or 

 less acid, and if left in cold machines will eat 

 away the metal. 



It may be said, in conclusion, that while 

 incubators are not for the slovenly, idle, or 

 capricious, where they are taken seriously and 



managed in regular business-like fashion, they 

 bring out upon an average a better per-centage 

 of fertile eggs than hens. In America that has 

 been settled beyond dispute, by averages calcu- 

 lated from thousands annually. So much is 

 this the case, that in that country it has worked 

 a profound revolution in the poultry industry. 

 Where eggs were formerly sold by the sitting, 

 the great majority are now sold for hatching at 

 so much per hundred, while some hatchers con- 

 tract by the thousand. The effect upon the 

 spread and popularity of non-sitting breeds has 

 been enormous upon both shores of the Atlantic. 

 Upon both sides of that international pond has 

 also been developed a considerable trade in 

 newly-hatched chickens, sold per dozen, or score, 

 or hundred, and sent off to the purchaser before 

 feeding, at from eighteen to twenty-four hours 

 old. Such are practical proofs of the undoubted 

 success now attained in artificial incubation. 



At this date it is not necessary to do more 

 than mention briefly the artificial system of 



hatching continuously under hen 

 Hen Turkeys turkeys which is still carried on 

 Incubators. t° some extent in France, though 



less than formerly, but has not now, 

 we think, been employed in England for many 

 years. Mr. Geyelin reported in 1865 that some 

 of the coitveurs, or professional hatchers in 

 France, had as many as sixty turkeys sitting 

 at once, the birds being fetched in from the 

 yards at any time when desired, placed upon 

 nest-eggs, and shut down under a lattice cover. 

 For about forty-eight hours they struggled more 

 or less to escape, but then settled down, and 

 afterwards would be kept sitting for three 

 months or more, the chicks being taken away 

 and fresh eggs substituted. The birds were 

 taken off once a day to feed and to clean the 

 nests ; they ate but little, and became very fat, 

 and after a time had to be given sufficient food 

 by cramming. When a bird had been sitting 

 for some time she could be made into a foster- 

 mother if desired, being given a glass of wine 

 at dark, and an hour or two after chickens 

 placed under her, which she would take to in 

 the morning. 



This system was at one time employed also 

 by English breeders to a small extent, but it 

 never appeared so successful as in France, 

 owing perhaps in part to differences in breed 

 and climate, but probably more to want of 

 experience and aptitude, which in France had 

 been hereditary for generations. Advances in 

 artificial hatching and rearing have made such 

 methods — in England and America at least — 

 now matters of only historical interest 



