66 



POULTRY APPLIANCES AND HANDICRAFT 



tightly, has eight holes bored in it. The center holes 

 are for a three-eighths-inch bolt seven inches long, with 

 a large flat head on one end and a thumbscrew on the 

 other. The other holes are for six escape pipes, which 

 are fifteen inches long and three-fourths of an inch in 

 diameter. Bore three holes on each side three inches 

 from the outside edges of the sides ; the first three 

 inches from the corner, the second fifteen inches from 

 the corner, the third twenty-seven inches from the cor- 

 ner, as shown in Figure 72, a. 



FIG 73 : VENTILATOR BOX FOR INCUBATOR 



Now cut two holes, eight inches from opposite 

 corners (one is shown in the drawing), in the center 

 of the sides and four inches in diameter ; and over both 

 the inside and outside tack stout pieces of tin contain- 

 ing round holes two and one-half inches in diameter. 

 These holes are for the lamp pipes, and the tin protects 

 the wood from fire. Directly under each of these holes 

 inside, nail a piece of tin a foot square, putting it half 

 an inch from the bottom, bending down the two cor- 

 ners not nailed half an inch. When the zinc is nailed 



