276 THE BELL SYSTEM TECHNICAL JOURNAL, APRIL 1951 



Fig. 1 — A typical small scale rotating batch type furnace employed in the production 

 of pyrolytic film resistors. 



phere. The linear velocity of gas passing through the coating zone is made 

 smaller than that through the preheating zone by expanding the coating- 

 zone diameter. This, together with the higher temperature of the preheating 



