324 
MINUTES OF PROCEEDINGS OE 
Mr Nasmyth received permission, in August, 1859, to convert his gun 
into a breech-loader, before rifling it, and in that state it was ultimately 
ordered to be tested to destruction. The gun burst on 21st September, 1859 
(Appendix II. p. 345), at the 27tli round, being the 7th round with cylinders 
of 96 lbs., charge 10 lbs. The Committee reported (No. 275, July 10, 
1859) their opinion that the system of breech-loading adopted was one 
which weakened the breech of the piece too much to allow of its application 
to the existing service guns, and no further steps have been taken to realize 
Mr NasmytlTs propositions. A 32-pr. gun, rifled by direction of the 
Secretary of State for War, on the system of the canon de 30 rayee of the 
Trench navy, has also been included; and lastly, a 32-pr., prepared by Sir 
William Armstrong, for some preliminary experiments on the shunt mode of 
rifling; but without any intention on his part of proposing it for rifling 
smooth-bored cast-iron guns. 
2. The whole of the guns selected were new 32-prs., of 58 cwt., of 
Messrs Hood's manufacture, cast and smooth-bored at Lowmoor. 
The metal of this foundry is distinguished by high specific gravity, and 
great tensile strength. The mean of 42 samples (enumerated Appendix III. 
p. 348), gives a tensile strength of 28,501 lbs. to the square inch, or 12*71 
tons. Tested by weight, suspended from a bar 2 inches square, and 10 
inches between the bearings, 11 samples gave a transverse resistance of 
27,969 lbs.; 7 samples cut 2 inches square, and 20 inches between the 
bearings, broke with a mean pressure of 9254 lbs. Comparing these results 
with the abstract of corresponding tests applied to 51 different makes of iron 
given in the Report of Colonel T, Eardley-Wilmot, in June, 1856,* the iron 
is sixth in the order of tensile strength, and third in resistance to transverse 
strain. It is fifth in density. 
3. The several systems of rifling may be described as follows 
Mr 13. Britten.—Gun rifled in 5 shallow grooves, one turn in 48 feet; 
projectile expanding, cylindro-conoidal, with lead envelop, attached by zinc; 
weight, empty, 47 lbs. 
Mr Lynall Thomas.—Gun rifled in 7 shallow grooves, one turn in 18 feet; 
projectile expanding, cylindro-conoidal, with lead envelop, attached mechani¬ 
cally; weight, empty, 55 lbs. 
Mr A. Jeffery.—Gun rifled in 7 circular grooves, one turn in 64 feet; 
projectile expanding, cylindro-conoidal, with lead envelop, attached mechani¬ 
cally ; weight, empty, 45| lbs, 
Mr J. C. Iladdan.—Gun rifled in 3 large circular grooves, with one turn in 
25 feet; projectile non-expanding, but cast with wings or projections corre¬ 
sponding in form to the grooves in the gun; weight, empty, 51 lbs.: an 
expanding wad was generally used, but latterly Mr Haddan employed a non¬ 
expanding wooden sabot. 
Mr C. W. Lancaster.—Gun oval-bored, difference of axis, *6 inch, one 
turn in 30 feet; projectile, cylindro-conoidal, but elliptical in section, and 
planed or turned with a skew corresponding to the bore; weight, empty, 
45f lbs. 
Cast-iron Experiments. Sessional Paper 497. 1856. 
