68 



In 18-gun frigate, " La Gloire," 



\M.r< v \M.r> \M . r' 



and finding means for x . y . 2 . (length, breadth moulded, and depth), of 

 immersed body, we get 



x -4 LL ^'r7E ' 4r7M = < L ' L 4rkV7v> 



y = li.vJ w^P 



V V R\ V. F ' 



« = ......... Ih.vJ ^'^' . 



L = length on water line ; j 



I = breadth, moulded ; > " La Guerriere." 



h = mean depth of immersed body j ) 



as ) 



y \ = ditto, 1 8-gun frigate. 

 V and M, solids immersed. 



Ny content of the parallelepiped described about the immersed 

 body. 



M 



Eatio between these last two solids = = R, 



M and R being the only variable quantities. 



On the 11th of December, 1863, Sir William Armstrong's " Big 

 "Will" was fired at Shoeburyness, and with what results will be seen. 

 This piece of ordnance weighs 22 J tons. It is what is technically termed 

 a built gun, being composed of eight coils of metal. It is rifled with 

 ten grooves on the shunt principle, and the shot is made to rotate by 

 means of ten rows of gun metal fitting into these grooves ; each row 

 contains five stems, and these stems, being made of softer metal than the 

 grooves, do not injure it ; the gun is fifteen feet in length, and the 

 internal diameter is 13 T %- inches, and the external diameter at the 

 muzzle one foot nine inches. At ten degrees elevation, the range is no 

 less than 4000 yards. The average weight of the shot is 600 lbs., and 



