468 
MINUTES OF PROCEEDINGS OF 
The number of rounds fired from service guns of the coil construction 
must now be counted by hundreds of thousands. 
Of the 9-inch guns alone there are seven that have all fired from 
500 to 707 rounds with battering charges of 43 lb. of powder, three of 
them having fired over 1000 rounds each of all kinds. 
The experimental firing at Shoeburyness has, in a great measure, 
consisted of trials of the service guns; and it may give some idea of the 
extent of these trials to state that more than 50 tons of gunpowder has 
been expended there annually in this manner. 
The essential feature of the Whitworth gun is the polygonal rifling, 
and for several years after Sir J. Whitworth's adoption of this mode 
of rifling, it appears to have been the only peculiarity in the guns by 
which they were entitled to bear his name. Thus we find that from 
1856 to 1858 all the Whitworth guns tried by the Government were 
made of either brass or cast-iron, the blocks from which they were 
bored being those in ordinary use for smooth-bore guns; and it is 
therefore clear that at that time there was no claim to originality or 
invention, as regarded either the material or the method of construction 
of the guns. 
Of these guns, the cast-iron ones, three in number, all burst, the 
most enduring of them lasting out only fourteen rounds; the brass 
ones were found to deteriorate by the expansion, and roughing or 
erosion of the bore, as well as by the wearing away of the angles of 
the rifling. The greatest number of rounds fired from any one of 
them was 460 from a 12-pr., when it became unserviceable, the bore 
having expanded more than one-tenth of an inch, and there being a 
large flaw in the bore half an inch deep. 
In 1862 a further trial of four brass 12-prs. was made, each of them 
firing 200 rounds, after which they were all reported unserviceable. 
The first Whitworth gun of compound construction made its appear¬ 
ance in 1859. It was an 80-pr. breech-loading gun, made with wrought- 
iron coils outside a steel tube—that is, on the principle advocated by 
Sir W. Armstrong—but the breech-loading arrangement was Sir J. 
Whitworth/s. The projectiles weighed from 68 lb. to 71 lb. each. 
Forty rounds were fired from it before it was purchased by the War 
Department. Only thirty-five rounds were fired from it at Woolwich, 
when it became unserviceable. The outer coil had shifted. There 
was a serious fracture in the inner cylinder, about 30 inches long and 
of considerable depth. There was great difficulty in opening or closing 
the breech, and the vent was completely closed' after fourteen rounds. 
In the following year a 12-pr. breech-loader made of homogeneous 
metal was tried. It fired in all 289 rounds at different times, the last 
date of firing being in September, 1865, when the breech-closing 
arrangement was blown off. 
These are the only two Whitworth breech-loaders of which we have 
any knowledge. Sir Joseph appears after their failure to have confined 
his attention altogether to muzzle-loaders. After this we find in 1861 
an account of four 70-pr. muzzle-loading guns, of which two Were made 
wholly at the ftoyal Gun Factories on the coil system, while the other 
two had barrels of Sir J. Whitworth's homogeneous metal, hooped with 
