48 COMPLETE INSTRUCTION IN 



as they will not retain dust. There should be 

 three ventilators, twelve by twelve inches, in the 

 ceiling, one over each aisle. These should be of 

 fine wire, to keep out insects, and should be so 

 fixed that a board may fall over them when 

 necessary to keep off the draft. There should 

 also be two ventilators in the roof, with wire 

 screens to use at will, and yet so arranged as to 

 keep out both rain and fog. 



It is advisable to have a trap-door in some 

 part of the ceiling, so that one can get up in the 

 garret if necessary. There should be three win- 

 dows on each side of the building, at equal dis- 

 tance from the ends and from each other. Also, 

 two windows in each end, one on either side of 

 the vestibule, which should be in the center. 

 This should be about five by six feet, with an 

 outside and inside door. The upper half of each 

 door should be glass. The utility of these vesti- 

 bules is to keep off sudden gusts of air from the 

 worms when the doors are opened. 



Have wire screens from top to bottom of all 

 the windows, which should open both above and 

 below. There should also be either inside slat- 

 shutters, or paper blinds, to adjust the light. 



A single board partition should divide the 

 building into two rooms. The smaller on the 

 east end, fifteen by forty feet; the larger, thirty- 



