1862.] 



17 



March 13, 1862. 



Major-General SABINE, President, in the Chair. 

 The following communication was read : 



" An Account of some Experiments with Eccentric Oblate Bodies 

 and Disks as Projectiles." By R. W. WOOLLCOMBE, Esq. 

 Communicated by Prof. STOKES, Sec. U.S. Received March 

 11, 1802. 



It is known now that, especially in the larger calibres, the rifle 

 principle has effected more for shells than for solid shot. A high 

 initial velocity, it appears, cannot be attained with this principle and 

 cylindro-ogival elongation ; this slow initial motion is, however, 

 but slowly lost ; while in a spherical projectile, such as the 68-pound 

 solid shot, the conditions are of a reverse kind. 



The object of this paper is to place before the Royal Society an 

 account of some experiments with models on a design which appears 

 to me likely in large guns to effect, not only an initial velocity greater 

 than that of spherical shot, but a terminal velocity better sustained 

 than that of rifle projectiles. 



Fig. 1. Fig. 2. 



Transverse section of 

 eccentric disk, of 

 actual dimensions. 



Side-view of disk, actual size ; eccentric by 

 a shallow and unfilled hole on each side 



Average weight of disk in cast iron, 7f ozs., 

 wrought iron, 8^ ozs. 



It is proposed to retain the circular periphery of a sphere only in 

 the line of motion, and by cutting away the opposite sides of a sphere 

 in parallel planes, say to half the radius, leave a disk, in that case with 

 a zone of 60 (fig. 1). 



VOL. XII. 



