282 



PKOF. W. A. BONE AND OTHERS ON 



chamber about 200 times by subjecting the vessel when in a horizontal position to a 

 slight rocking motion. This is an important precaution in experiments of this 

 kind, the omission of which may vitiate the results owing to imperfect mixing of the 

 charge and stratification effects. 



(2) The Bomb with Spherical Explosion Cavity (Bomb B, figs. 5 and 6) was like- 

 wise machined from a solid forging of open-hearth acid steel, out of the centre of which 

 was cut the spherical cavity, A, 3 inches in diameter (capacity approximately 275 c.c.). 

 The body, B B, of the bomb is cylindrical in outline, its axial length being 10 '2 5 inches, 

 and its diameter 8 inches ; it is mounted on a cast-iron stand by means of ball bearings 



B 



Fig. 7. 



Fig. 6. 



Fig. 8. 



which permit of a rapid rotational motion of the bomb on its axis in order to ensure an 

 effective mixing of its gaseous contents before an explosion. C, C, are steel stops 

 which may be inserted against the plugs, D, D, when it is desired to keep the body 

 of the bomb at rest. 



The bomb is fitted with the coned valve, E, and a plug, F, and also with a special 

 joint, G, carrying an insulated ignition plug, H, of similar design to that used in the 

 case of the aforesaid cylindrical bomb A. All joints are metal to metal, and capable 

 of holding up a pressure of 1000 atmospheres, which was the testing pressure to which 

 the bomb and all its fittings was submitted. 



