28 



STUDIES OF POULTRY. 



it through underground pipes, at definite cost, to dealers in perish- 

 able goods, thereby saving them the maintenance of refrigerating 

 machinery. A considerable number of city blocks are frequently 

 traversed by these pipes, and large markets as well as individual 



shops are thus supplied with the refrigeration required for the espe- 

 cial kind of produce carried. Not only are insulated rooms so chilled, 

 but holders of market stalls may have boxes mechanically cooled for 

 holding supplies and show cases for the displaj^ of goods. 



[Cir. 64] 



Figure 9 



