THE DOMESTIC FOWL. 115 



The fowl leaves her nest every day in search of food 

 for twenty or thirty minutes ; this must be imitated 

 also, as the temporary loss of heat has the effect of 

 causing the contents of the egg to diminish in bulk, 

 and the vacuum is formed by a fresh supply, (of air,) 

 drawn in for the nourishment of the germ. The eggs 

 must be moved three times a-day, morning, noon, and 

 night, which prevents the adhesion of any part of the 

 fluid to % the shell, and gives the small blood vessels 

 better opportunity to spread around the surface of the 

 egg. This is effected by nature ; when the fowl leaves 

 her nest or returns to it, she naturally disturbs the 

 eggs, and also from any change she may make in her 

 position while upon her nest." 



Mr. Cantelo thus describes the hydro-incubator: 

 " The form, or method considered by the inventor, as 

 best calculated for the application of top-contact heat 

 to eggs during incubation is that of a current of warm 

 water flowing over an impermeable or water-proof cloth, 

 beneath which the eggs are placed. This is effected 

 on a large scale by pumps, and in a small apparatus 

 by the law of gravitation causing the warm particles 

 to rise, and those that have become partially cooled to 

 fall. A tank of water is kept continually at a tem- 

 perature of 109 F., from the surface of which it will 

 naturally flow over the water-proof cloth, a return pipe 

 being so placed as to connect the outer end of the 

 cloth with the bottom of the tank. The eggs are 

 placed in drawers having open work or perforated bot- 

 toms, and they are laid on a piece of thin woollen 

 cloth. The drawers are placed beneath the incubator, 

 and raised so that the eggs come in contact with the 

 water-proof cloth, but so as to allow a space between 

 the sides of the drawers and the incubating cloth. 

 These sides being lower than the top of the eggs, space 

 is afforded for the air to circulate around them, as it 

 rises through the bottom and passes out over the edges 

 of the drawers." 



Within two or three years past, an apparatus has 



