144 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 3 



ferent constant temperature: No. 1 at 60°, No. 2 at 50°, No. 3 at 

 43° and No. 4 at 32°. The radiating surfaces of the coils were 

 estimated to easily maintain these temperatures, being 453, 733, 

 1,153 and 1,453 square inches respectively. 



In one side of each chamber is a door 15 inches each way, which 

 seats on two felt-lined surfaces and is fastened by the usual eccentric 

 refrigerator door hasp. In each door is a window, 9 by 10 inches, 

 containing six panes of glass with five air spaces between (PI. 8). 



\\\\\\\\\\\\\\\\\\\\\\\\\T^ 



Fig. 27. Section through wall of cool chamber, showini 

 and balanced valve with connections. 



thermo-regulator 



The insulation of these chambers is so nearly perfect that there can 

 be but little loss through the walls. 



The desired temperatures are secured by pumping the cold brine 

 through the coils, which are placed in the upper part of the chambers. 

 This arrangement allows the free use of the floor of the chamber 

 and also locates the coils at the point of higliest temperature and 

 theoretically should yield the best results. Inside the chambers and 

 just below the coils are located the bellows of the thermo-regulators. 

 This location gives a quick response to any changes of temperature 

 'of the coils themselves. 



