20 FARMERS' BULLETIN 851. 



junior author and constructed under his supervision. The manure, 

 instead of being thrown on the ground, is heaped carefully on a 

 slatted platform, which stands about 1 foot high. This particular 

 platform measures 10 by 20 feet. There are six 2 by 4 pieces running 

 lengthwise 2 feet apart. Across these are nailed 1-inch strips with to 

 1 inch spaces between them. The wooden platform stands on a con- 

 crete floor, and a rim or wall of concrete 4 inches high surrounds the 

 floor. The floor slopes a little toward one corner, from which a pipe 

 leads to a small cistern near by. This pipe is plugged with a stopper 

 of soft wood, and the concrete floor is filled with water to a depth 

 of 1 inch in the shallowest part. The manure is then heaped on the 

 platform each morning when it is removed from the stable. Flies 

 will lay their eggs on the manure as usual, but the maggots, when 

 they have "finished feeding and begin to migrate, crawl out of the 

 manure, drop into the water below, and are drowned. Each week 



FIG. 15. Imaginary cross section of an arrangement suggested for use where manure production is large, 

 a, Pump; c, concrete floor and walls of cistern; o, outlet pipes leading from floor of maggot trap to 

 cistern; p, platform maggot trap; t, cistern for liquid manure; g, ground level. (Hutchison.) 



the plug is removed from the pipe, and all the maggots are washed 

 into the cistern. The floor is then cleaned -of any solid particles by 

 means of a long-handled stable broom or by a strong stream of water 

 from a hose. The pipe being again plugged, the floor is again partly 

 filled with water and the trap is ready for another week's catch. A 

 platform of this size will hold the manure accumulating from four 

 horses during the period of four months, or about 20 days' accumula- 

 tion from 25 horses, if the heap is well built and made at least 5 feet 

 high. 



Experience with maggot traps has brought out the following 

 points : In the first place, the trap is more effective when the manure 

 is kept compactly heaped and well moist. This is to be explained by 

 the fact that the larvae seek a comparatively dry place in which to 

 pupate, and crawl away from wet manure. A cistern should be built 

 close to the trap and a pump fitted so that liquids can be pumped 

 onto the heap. (Fig. 15.) Each day, after the litter from the stable 



