FOR SITTERS IN MILD CLIMATES. 77 



operations about the nests, from either end of a building 

 one hundred and fifty feet long, without going down 

 the alley. 



Figure 25 shows the operation of a treadle, T, at the bot- 

 tom of one of the separate passages, leading to a separate 

 nest, this treadle being operated by the weight of the 

 hen, which releases a figure 4 catch and closes the pas- 

 sage door, thus confining her and shutting laying fowls 

 out. In this cut, the sides and top of the nest and of 



FIG. 25. APPARATUS FOR SITTERS. 



the passage leading to the nest, and other things in the 

 vicinity are omitted ; the purpose being merely to show 

 how the hen shuts herself in. The treadle, T, eleven 

 inches wide, or just enough scant to play freely in an 

 eleven-inch space, and twenty inches long, forms the 

 bottom of the passage, which is large enough to admit a 

 fowl and allow her access to the nest, b. In this cut, an 

 edge view is given of the door, 7^, pivoted at n, and raised 

 by the cord, a\ which passes over the pulley, p. 



