78 AN EGG FARM. 



Attached to the door is the door lever, k, this lever 

 being held down by a figure 4 catch. This we call the 

 first position of the door. The hen enters on the treadle 

 at T and walks toward the nest at ft. The treadle, being 

 moved downward by her weight, turns on the pivot, v v, 

 which has bearings on the side of the passage not shown 

 in this cut. To the treadle is attached a rod, jointed at 

 t and pivoted at e and at x. When x moves downward, 

 as indicated by the arrow, the motions of the other parts 



FIG. 26. APPARATUS FOR SITTERS. 



are also in the directions of the arrows, t going down- 

 ward and toward the right and the figure 4 toward the 

 left, releasing the door lever, and causing the door, h 1 , 

 to fall by its own weight and close the passage. When 

 the door is shut, it is in the second position, and it 

 stands, not perpendicularly, but on a slant, as shown at 

 h 2 , Fig. 26. In this cut, the top and one side of the 

 passage and nest are shown, which, of course, hide the 



