744 



TRUEBLOOD. 



and Fig. 6 (front elevation). 



The oil bath and its contents (second- 

 ary superheater, stirrers, etc.), 

 shown in these figures are as used 

 with the straight-away type of 

 plug described under II, 2, d 

 above. A complete reconstruction 

 of all of this section of the appar- 

 atus was necessitated by the adop- 

 tion of this type of plug. The 

 remainder of the apparatus, aside 

 from a few minor changes, was 

 unaltered by the change from the 

 vertical to the horizontal type of 

 plug. 



o 





c3 



o 

 o 



1. Oil Bath and Secondary 

 Superheater. 



>-. 



a 

 I 



bC 







Only the bath and superheater 

 used with the straight-away plug 

 will be described in detail. 



The oil is contained in a rec- 

 tangular tank (Figs. 5 and 6),. 

 41 X 18 X 13 inches. The last 

 dimension is the depth. The tank 

 is of sheet iron, galvanized after 

 construction. It is heavily lagged, 

 on the four vertical sides and the 

 bottom, with asbestos, and when 

 running, the top is completely 

 covered with an asbestos cover 

 about 1| in. thick. The two long 

 vertical sides and the bottom are 

 lined on the inside with a series of 

 8 German-silver heating coils (Ci, 

 Co. . . .Cs, Fig. 5) ; each coil takes 

 about 300 watts at 110 volts. At 

 each end of the tank is a small 



circular aperture (not shown) ordinarily closed with a flange. 



Removing the flanges, after draining the oil from the tank, makes it 



