BRIDGMAN. — ACTION OF MERCURY ON STEEL. 



327 



the water. This explanation, however, was opposed by all previous 

 experience with this steel. In any event, the effect of the mercury was 

 entirely different from that found by Amagat, as there was never any 

 tendency for the mercury to S({uirt through the 

 steel, but there was always sudden rupture, the 

 cylinder cracking down one side in a plane con- 

 taining the axis. To show conclusively that a 

 cylinder of hardened nickel steel will really not 

 stand so much pressure when the transmitting 

 liquid is mercury as when it is some other liquid 

 such as water, the following experiment was under- 

 taken. A bar of this special steel (Krupp Special 

 Chrome Nickel Steel E. F. 60.0) was cut into 

 twelve pieces each 8^" long and 2" diameter. 

 (See Figure 1.) The pieces were numbered and 

 their orientation in the original bar carefully 

 noted. They were then each pierced with a ^' 

 hole reamed to size, turned on the outside true 

 with the hole, and hardened by heating to a bright 

 cherry red and quenching in a heavy tempering 

 oil. Every other cylinder (Nos. 1, 3, 5, 7, 9, 11) 

 was filled with mercury and tested by applying 

 pressure to the mercury by means of a piston 

 actuated by a hydraalic press. The test condi- 

 tions of these different cylinders were varied some- 

 what by changing the rapidity with which pressure 

 was applied ; in other respects the conditions were 

 the same. The other cylinders were tested in a 

 similar way, except that the fluid transmitting the 

 pressure was not mercury; being in four of the 

 six cases water and glycerine, in the others ether 

 and carbon disulphide respectively. The pressure 

 in the test cylinders was determined from the 

 pressure of the fluid actuating the hydraulic ram, 

 multiplying in the ratio of the areas of the two 

 pistons. An unknown error is introduced here 

 by the friction of the packing, but in other experi- 

 ments with similar cylinders in which the pressure inside the small cylin- 

 ders was measured directly it was found that the error so introduced was 

 nearly constant and easy to correct for. The correction so found was 

 used in the results to be given. In any event, the correction is less 

 than the irregularities introduced by other causes. 



Figure 1. Form 

 of the test cylinders 

 broken with mer- 

 cury. 



