THE ALTERNATE AND PARALLEL SYSTEMS. 219 



such a way that it will be wound up on the pipe when 

 the latter is turned, by means of a large hand wheel, Fig. 

 133, which is attached to one end of the pipe within 

 reach of the operator. 



The windows may all be opened a fraction of an inch, 

 or several inches or wide open, with the greatest ease 

 and dispatch in two or three seconds, and partly or 

 wholly closed as quickly, and can be moved many times 

 a day to suit varying wind and weather, a very impor- 

 tant thing which would be impossible if each window 

 were to be moved by hand. In a large establishment, 

 like ours photographed for this book, there are several 

 hundred windows, and it must be recollected that violent 

 gales sometimes rise so suddenly that twenty men or fifty 

 men could not close them all by hand quickly enough. 

 The set of windows in Fig. 132 is on the same side as the 

 tilt boxes, and a similar row of windows is supposed to 

 be on the side not shown in this cut. The yards are also 

 on the side not shown, but their position is indicated by 

 y in Fig. 117. 



Figure 117 gives a tran verse section substantially 

 through m in the ground plan, Fig. 135. The yard fences, 

 y, run in a direction parallel to the end walls of the build- 

 ing and enclose as many yards as there are tilt boxes. 

 The posts, 6' 1 and 2 , reach to the roof. The short post, 

 Ic, forms one of the supports to the passage platform, g. 

 This platform is the principal line of travel used by the 

 attendant, who can, however, also go the whole length of 

 the building between c l and the wall, but in doing so 

 must open a door at each room he passes through. 

 Nearly all the work is done in passage, g. Labor saving 

 forbids handling doors, except when unavoidable, and, 

 be it repeated, commercial poultry keeping can be prof- 

 itable only when the utmost care and ingenuity are 

 employed in every operation, from a to izzard, to save 



