The Hon. Sir Charles Parsons 



[Jan. 23, 



It has beeD suggested with the object of reaching higher pressures 

 thai a Bmall die might be bodily immersed in a large container; 

 doubtless it could be arranged, but it would be very cumbersome to 

 work with, and would only add about 100 tons per square inch to the 

 maximum pressure. 



A better plan would lie to follow the principleof the usual capped 

 armour-piercing projectile, and to reinforce the rams and ends of 

 the container by tightly fitting copper or bronze rings around the 

 necks of the rams, keeping the parallel part of the noses as short as 

 possible (Fig. 3). 



When in operation the copper rings will be flattened and squeezed 

 against the necks and shoulders of the rams, and also against the 

 ends of the container, and by this means the parts that ordinarily 

 would have to bear the maximum stress will have part of this stress 

 transferred to other parts not so heavily stressed, and consequently 



Cef>/>£/9 o/? /2&oe*Z£ 4?vV 



9J 



Fig. 3. 



the maximum pressure in the container can by this means be raised 

 considerably, perhaps to 450 tons per square inch. 



In carrying out experiments on larger samples of material, and 

 in applying electrical heating to the charge, the container becomes 

 too large to permit of its being made of hardened steel ; therefore 

 nickel steel is used, as for the barrels of guns. It is heat-treated by 

 quenching in oil from a high temperature after rough machining. 

 Containers < Figs. 4 and 5) with the thickness of wall equal to the 

 diameter of the bore will stand an internal pressure of 40 tons per 

 square inch repeated almost indefinitely without serious enlargement 

 of the bore ; but 100 tons necessitates reboring and the fitting of new 

 packing to the ram after each experiment. 



Fig. I shows the arrangement for electrically heating con- 

 ductor.- immersed in fluids under high pressure. The packing of the 

 ram is a cup, leather, backed by a cup of brass ; the leather first takes 

 the pressure and the lip of the brass cup is thereby expanded tightly 

 against the Lore of the container and remains fluid-tight, "even 

 though the leather should be carbonized bv the heat. The bottom 



