POULTRY. 563 



that they all had diseased lungs, and were afflicted in the same manner as those which have 

 several times been submitted to the experience of the pneumatic machine. I therefore con 

 cluded that there was a failure of air; indeed my incubator was so air-tight that there was 

 no loss of heat, and even my opening the door twice a day did not suffice. At last, after 

 groping first here and then there, I constructed an incubator which, I believe, unites all the 

 required conditions. 



This incubator consists of a rectangular wooden case about forty inches in length, twenty 

 inches high, and about thirty inches wide. This fits upon a wooden bottom, supported by 

 two hooks, to enable it to be readily taken apart for cleansing purposes. In this case a 

 reservoir of zinc is placed horizontally (the capacity of this reservoir being about eighteen 

 gallons), which divides the case into two compartments. This reservoir is filled and emptied 

 by a system analogous to that of other incubators. The water in the reservoir is kept at a 

 constant temperature by two gas burners, which enter into the boilers and traverse the 

 reservoir from side to side. A collecting pipe distributes the gas in the burners, and is 

 provided with a mercurial regulator placed on the inside. This regulator is nothing more than 

 a strong thermometer with a hole in its side, through which the gas passes to its destination. 

 This hole is opposite the 102 mark. 



The opening giving passage to the gas finds itself entirely stopped when tha temperature 

 reaches the desired height. The mercury forms an obturator, and regulates the heat to one- 

 tenth of a degree, nearly. It is indeed completely impossible, without regulating anew this 

 thermometer, to raise the heat beyond the necessary point. With this regulator there is no 

 pressure nor change of heat in the gas. In the absence of gas two small lamps with a flame 

 capable of being regulated; a hole is made in these burners and the products of combustion 

 escape by means of two openings behind the apparatus. In order to give the eggs the amount 

 of moisture necessary for incubation, there are two small holes with funnels soldered around 

 them, and with movable plugs, which permit the steam from the water in .the reservoir to 

 spread itself in the egg chamber and keep there an atmosphere always moist. Over the 

 reservoir are two air tubes pierced with small holes (.035 inch in diameter), the one coming 

 in at the right side and going over to the left; and the other coming in on the left, and going 

 over the right side, carrying the fresh air over the eggs and removing the carbonic acid gas. 



The air, in thus entering, becomes warm in its whole course over the reservoir, and does 

 not chill the eggs. The air is thus in the same condition as that which has passed through 

 the feathers of the natural mother. About two inches above these tubes we find a screen 

 coming to about an inch from the side of the case (the same space being left in the middle). 

 This screen is composed of three layers, the bottom one of zinc, then one of wood, and the 

 third of swan down, with a little cut straw thrown over this top layer. The eggs are placed 

 upon this bed, and the zinc below, being highly polished, permits the heat to glide along the 

 surface and pass through by the opening in the middle of the screen, and those between the 

 screen and sides of the case to become stored up in the chambers. The heat is stopped above 

 by two glass plates with a stratum of air between them, and redescends upon the eggs, caus 

 ing the last ones to be heated from above, although they are placed over the reservoir. 



I have thus been able to leave chickens in the hatching chamber for twenty-four hours 

 after hatching, without any injury whatever, after their successful entree into the world. 

 The chamber below, being furnished with air in the same manner as the one above, 

 serves as an artificial mother. A small door made in front gives the liberty of ingress and 

 egress to a rearing door; a door placed behind permits one to have an eye upon them. This 

 incubator being closed above by two superimposed panes of glass, renders the different phases 

 of hatching visible to everyone. To sum up the advantages, we find: 



1. It is absolutely impossible to give the eggs more heat than is necessary for them. 



2. A regulator permitting you to modify this heat in proportion as the embryo increases 

 its vitality. 



