A GUIDE FOR KEEPERS OF POULTRY 193 
nations learned the art of incubation from the other the 
incubators they use are very much alike, being mud ovens 
heated in Egypt by burning dried camel dung and in 
China by burning twigs and straw. The incubators them- 
selves are rude mud ovens without any attempt at careful 
ventilation and without means to regulate the tempera- 
ture. Not even a thermometer is used to determine the 
temperature, the operator judging this from his own sen- 
sations when he enters the incubator to take care of the 
eggs. For more than a hundred years scientists have 
been struggling with the art of incubation in this country 
and Europe, yet up to this time an unlearned Egyptian 
fellah or a Chinese coolie is able to produce results the 
equal of those produced by the best machines of this kind 
made in any country. 
The first mention of the artificial incubation of domes- 
tic fowls occurs in the writings of Aristotle. Later Pliny 
relates that the Roman empress Livia hatched chickens 
in her bosom, a very doubtful story in the light of our 
latter-day knowledge that the temperature required to 
bring chickens to perfection is 5° higher than that of the 
human body. The first authentic account of artificial in- 
cubation outside Egypt and China is of a machine in- 
vented by Rene Antoine Ferchault de Reamur,the French 
inventor, to whose credit stands the thermometer which 
bears his name. Reamur lived from 1683 to 1757, so the. 
authentic history of artificial incubation in civilized coun- 
tries extends back at least 150 years. The machine in- 
vented by Reamur is figured in “The American Poul- 
terer’s Companion” (1847), from which work our illus- 
tration is reproduced. Reamur published a work of 500 
pages treating on incubation, in which he said the proper 
temperature was 90°. This must have been according to 
