76 GENERAL MANAGEMENT I>F POULTRY. 



still very large compared with those formerly employed, while 

 the horizontal partitions are more or less essential. These 

 incubators are made as small as for three dozen eggs, one of 

 which size can be obtained for about thirty shillings ; but the 

 experience of many persons has proved that the size for 

 ninety or a hundred eggs is the most generally useful one, and 

 on the whole gives most satisfactory results. Such a machine 

 now contains about fifteen to twenty gallons of water, and 

 the following is the mode of operation with it : The machine 

 should have a place free from strong, cold draughts, if possible. 

 When fixed it must be filled up entirely with boiling water, 

 which is left in for twelve hours, and must then be entirely 

 drawn off by tipping the machine forward and opening a tap 

 at the bottom of the tank (this tap in ordinary work is not 

 used at all). The machine is then filled up with boiling water 

 the second time. This process is absolutely essential to 

 thoroughly ** charge " the whole machine and its packings with 

 the necessary heat. Twelve hours after the second filling the 

 thermometer should be put in, and as soon as it falls to 

 106 (which will not be till rather later) the eggs may be 

 placed in the drawer on flannel. In very frosty weather the 

 flannel may be doubled with advantage. Also at the same 

 time wet the earth-trays, and draw off from two (in warm) to 

 three (in cold weather) gallons of water by the working tap, 

 replaced by boiling water. The supply of heat must now be 

 attended to every twelve hours, and about the same hour. At 

 each visit the water drawn off will probably be from 136 to 

 140, and must always be tested by the thermometer, as this 

 figure is the guide for the quantity of boiling water to put in. 

 But the heat of the drawers, which is also examined, is another 

 guide. As a rule, if the room be about 60, from two and a 

 half to three gallons may be required, which may rise to six 

 gallons in cold weather in a cold room. The heat added in 

 this way is very slowly and equably percolating downwards all 



