TANK LID 



Construction and insulation of the main tank lid 

 (fig. 2) are similar to those of the main tank body. The 

 frame and sheathing are of 3/4-inch marine plywood and 

 wooden 2-by-4's, and the insulation consists of 4-1/2-inch 

 corkboard. Guide rollers (fig. 1) keep the lid caged be- 

 tween the four aluminum pipe legs used to support the tank. 

 The lid can be raised 30 inches by means of 5/32-inch 

 stainless-steel lifting cables attached to its corners. These 

 cables pass over pulleys mounted at the top of the aluminum 

 legs and go down through the legs to a point just below the 

 bottom of the tank. Here the cables exit through holes 

 and pass, via other pulleys, to a cable drum which is 

 suspended from the bottom framework of the tank and 



STIRRING MOTOR 



GEARED TIMING BELT 

 INDEXING MOTOR 



PLATINUM 

 THERMOMETER ENTRY 



QUARTZ 

 THERMOMETER ENTRY 



YOKE RELEASE LEVER 



STIRRING MOTOR 



CALIBRATION TANK LID 

 (VIEWED FROM LEFT SIDE) 



Figure 2. Calibration tank lid (view from left side). 



