Chickens form an essential part of the stock upon many farms. The Twelfth Census shows that there were 5,737.372 farms in the United States in 1900, and it is safe to say that those which did not have chickens among the stock were very few indeed. The Census also shows that there were 250,681.593 fowls (chickens, turkeys, geese, and ducks) in the United States. This gives an average of forty-two to every farm. The value of all fowls on farms in 1900 was $85,794,996, producing for market in one year poultry worth $136,891,877 and eggs worth $144,286,370, a total value of $281.-178,547. The investment has yielded an income of 40 per cent. In seeking for the cause of the great success attending poultry raising, one must not overlook the great amount of work done by the mechanical incubator, which is not only as fully successful as the hen, but works on a large scale.