736 



TRUEBLOOD. 



soapstone block S', through another set of holes in block S similar to 

 those shown, past the low side thermometer bulb, and out through an 

 orifice (not shown) in cap C. The head of the low side thermometer 

 may be seen projecting from the cap C". The two sets of holes 

 in the block S are threaded with a continuous piece of wire, used as a 



INSULATION 



^ — G3 — CT ^ 



Figure 1. Axial flow plug and plug case. 



heating coil when it is desired to conduct the experiment isothermally 

 for the measurement of nCp. This wire in certain plugs was of solid 

 manganin, in size approximately No. 18 B. and S. gauge; in others, it 

 was of stranded invar, ten strands, each about 0.01 inch in diameter, 

 being used. Connections for the differential pressure gauge are 



