BER THEL OT'S CAL OKI ME TER. 



49 



8' 



Fig. 17 shows the bomb adjusted ready to place in the 

 calorimeter. Full details of the construction 

 will be found in Berthelot and Vielle's treatise, 

 Sur la force des metiers explosives, vol. I, p. 

 245. 



Fig. 21 shows the arrangement adopted 

 by Berthelot to burn solids. The cylinder 

 (Fig. 1 8) is lined with platinum, and con- 

 structed so as to resist a pressure of 200 to 

 300 atmospheres. It is furnished with a 

 tight-fitting head (Fig. 17) fastened ex- 

 teriorly by a piece of steel (Fig. 19), clamped 

 on the external face of the bomb by a screw- 

 clamp (Fig. 20), which does not form a part of the apparatus 

 as immersed. 



The sealing of the bomb results from the adherence of 

 the margin of the head BB (Fig. 21), and the interior of 

 the cylinder, and also between the platinum of the head and 

 the platinum of the cylinder. Berthelot makes the joint 



FIG. 17. 



FIG. 18. 



FIG. 19. 



FIG. 20. 



tight with a smearing of vaseline around the opening, being 

 careful not to have a trace on the inside. If no bubbles 

 escape on putting it into the calorimetric bath, the joints are 

 tight. 



The cover is pierced at the centre with a small hole, in 

 which is fitted a tube formed of a hollow screw acting as a 

 cock, and itself provided at the upper end with a circular 

 head. The electric ignition is produced by a platinum wire 



