Melting Points of Certain Metals. 



503 



secured automatically, and a pressure-tight closure of the bomb 

 thereby insured. 



Fig. 1. 





Fig. 1. General arrangement of apparatus. The bomb is drawn to scale ; 

 the rest of the apparatus only approximately so. Pressure is supplied by 

 the pump D, and transmitted through the system by means of a paraffin oil 

 which has at the same time a high boiling point and low viscosity. F is a 

 steel bottle of about one liter capacity ; it serves to increase the volume of 

 the system. The valve V (shown in detail in fig. 2), is used to lower the 

 pressure in the system. M is a Bourdon gage graduated to 3000 atm. in 

 divisions of 50. The connection block C affords a 4-way connection 

 between pump, valve, gage, and bomb. The latter consists essentially of a 

 ring of nickel-steel RR, and a number of rings of boiler plate shrunk on to 

 a cylinder of steel KK. On the outside of the rings is shrunk a thin cylin- 

 der. The cooling water enters at W x and leaves at W t . The bomb is closed 

 by means of the steel plugs G and H, which are held in place by a hydraulic 

 press the platens of which are shown at PP. The curved surfaces of A and 

 B on one end and of A and G on the other constitute the essential parts of 

 the device used for securing alignment of bomb and plugs. JJ is the 

 electric furnace (for details see fig. 3), and SS soapstone blocks for thermal 

 insulation at the ends. Thermocouple wires are shown at TT, and heating 

 current wires at Z. 



