68 POULTRY APPLIANCES AND HANDICRAFT 



twelve tin pipes to furnish ventilation from below. 

 These pipes are eight inches long. The sides of the 

 ventilator box extend out even with the bottom of 

 the incubator for the drawer to slide on. 



Having made this, place the drawer on it, and 

 the heater on the drawer, and fasten the heater and 

 ventilator together with boards nailed on the sides 

 and back. The boards should be one foot wide, and 

 be nailed so as to allow the drawer to work nicely 

 between the heater and ventilator. These boards on 

 the sides must project the same at the front as do the 

 sides of the ventilator. Next fit an eight-inch board 

 over the front of the drawer, keeping it level with the 

 zinc. This keeps the sawdust from falling into 

 the drawer. 



Now with the bottom as a guide, build the outer 

 box for sawdust, making it nine inches higher than 

 the top of the heater, and taking care to fit the front 

 boards around the end of the drawer nicely. To 

 allow the lamp pipes to enter, cut holes in the outer 

 box the same as was done in the heater, but using tins 

 on the outside only. Where the lamp pipes pass 

 through the sawdust, a box for sand must be made 

 of sufficient size to properly protect the sawdust. The 

 tinsmith must make the lamp and escape pipes as 

 stovepipe is made, but the ventilator pipes may be 

 soldered, as they are in no danger of melting. The 

 escape pipes must be cut off so as to come to a point, 

 so that when they are pushed down and touch the 

 zinc, only a small draft is allowed, and the draft cannot 

 become closed. 



The lamp pipes should be two and one-half inches 

 in diameter, with elbows in them allowing the pipes 

 to extend into the heater three inches at one end, and 

 at the other end to fit a tin lamp chimney with an 

 isinglass window in it one inch in diameter. This 



