300 THE HOUSE FLY— DISEASE CARRIER 



top near the ends, to prevent warping; it is hinged in 

 back to a strip i inch thick, 3 inches wide, and 20 

 inches long, which is fastened to the seat. Cleats 

 may also be nailed on the seat at the sides of the cover. 

 On the inside of the backboard, 12 inches above the 

 seat, there should be nailed a block ( i ) , 2 inches wide, 

 6 inches long, extending forward 334 inches; this is 

 intended to prevent the cover from falling backward 

 and to make it to fall down over the hole when the 

 occupant rises. 



On the floor of the box (underneath the seat) two 

 or three cleats are nailed in such a position that 

 they will always center the tub; the position of these 

 cleats depends upon the size of the tub. 



Back door. — In making the back of the privy the 

 two center boards were sawed at the height of the 

 bottom of the seat. The small portions (c^) sawed 

 off (23 inches long) are cleated (O) together so 

 as to form a back door which is hinged above; a 

 bolt or a button is sufficient arrangement to keep the 

 door closed. 



Front door. — The front door, Fig. 38, is made by 

 cleating (/>) together three boards (Q) i inch thick, 

 10 inches wide, and (when finished) 6 feet 7 inches 

 long; it is best to use three cross-cleats (/>) (i inch 

 thick, 6 inches wide. 30 inches long), placed on the 

 inside. The door is hung with two hinges (6-inch 

 "strap" hinges will do), which are placed on the right 

 as one faces the privy, so that the door opens from 

 the left. The door should close with a coil spring (cost 



