About the year 1862, a Mr. Thompson, of Bilston, took out a patent for a novel and ingenious mode of manufacturing Enfield rifle-barrels, and after many trials he chose Bessemer mild steel as the material most suitable for this purpose. Our works at Sheffield supplied him with large quantities of mild steel, in the form of round bars 3 in. in diameter. These were afterwards sawn into lengths of about 6 in., and when made red-hot were placed on end under the steam-hammer, which carried a cylindrical steel punch of 1 in. in diameter, having a conical end resembling an armour-piercing shot, as shown in Fig. 61.

The hammer A had projecting from it the punch B, beneath which was placed the steel piece C, shown partly pierced by one or two blows. This piece was placed over an opening in the anvil block D, and after two or three more blows it was pierced from end to end, forming a short tube from which no metal has been removed. This violent treatment did not split or injure the steel in any way, but was well calculated to show any defect if the metal operated upon was not absolutely sound. After the operation of punching, the short tubular piece was rolled between a pair of rollers having a series of tapering grooves formed on them, and also an enlarged recess to form the breech part out of the solid, so that a barrel in one piece without welding was produced. This was afterwards finished in the usual way. The severe test to which these mild steel barrels were subjected at the Proof House, Birmingham, is shown in the annexed tabular statement, which is taken from a Paper read by me at the Royal United Service Institution on May 2nd, 1864, and published in the Transactions, from which the Table herewith given is copied.

TRIAL OF TWO STEEL GUN-BARRELS (ENFIELD PATTERN), AT THE PROOF-HOUSE, BIRMINGHAM.
Barrels made from Bessemer Steel by Thompson's Patent process.
Barrels, 1853 Infantry Pattern, .577 bore. Bullets used, 715 grains. Diameter, .551 Length, 1.043. Ratio of length to diameter. 1.893.

 Result of
Experiments:
1st round, charge 205 grains, 7 1/2 drachms powder, 1 bullet.
2nd round, charge 224 grains,
8 1/4 drachms powder, 1 bullet.
3rd round, " " 2 bullets
4th round, " " 3 bullets
5th round, " " 4 bullets
6th round, " " 5 bullets
The barrels were now examined and found intact.
7th round, charge 224 grains,
8 1/4 drachms powder, 6 bullets
8th round, " " 7 bullets
9th round, " " 8 bullets
10th round, " " 9 bullets
11th round, " " 10 bullets
12th round, " " 11 bullets
13th round, " " 12 bullets
14th round, " " 13 bullets
15th round, " " 14 bullets
16th round, " " 15 bullets
Barrels found intact.
17th round, charge 224 grains,
8 1/4 drachms powder, 16 bullets.

 18th round,
charge increased to 269 grains, 9 3/4 drachms powder, 17 bullets.
19th round, " " " " 18 bullets.
*20th
round, " 413 " 15 " " and 25 bullets.

With these examples of the extraordinary toughness and tenacity of both pure Bessemer iron and Bessemer steel, no one, with any knowledge of the violent strains to which the test pieces were subjected, can doubt the fact that between the copper-like toughness of the pure Bessemer iron, and the great tenacity of the more highly carburised steel which we were at that time supplying to engineers, for making every description of cutlery and cutting tools, there did exist, and could easily have been found by trial, the precise quality of steel most suitable for the construction of ordnance. It must be borne in mind that it was not until some ten years later, that is, in the year 1869, that any Siemens-Martin, or open-hearth steel, was made, and consequently that the only varieties of cast-steel then available for guns were crucible cast-steel and Bessemer cast-steel. The fact must also be recognised that both the difficulty and the cost of producing large masses of crucible steel increased greatly whenever the metal was required to be of the very mild quality known as low carbon steel, which is most difficult to fuse in crucibles, as well as to retain in fusion during the time occupied in filling a large mould from hundreds of separate small vessels. Hence the strong temptation the steel manufacturers had to supply a more carburised, and consequently a more easily fusible and less tough, steel than was specified; while the price of this crucible steel was greatly augmented as the ingot became larger, increasing to over £100 per ton. It is equally notorious that not one of these disadvantages applied to the Bessemer metal; it was, in fact, cheaper to produce a single mass of 10 or 20 tons in weight than to make the same weight in a number of small batches of 3 tons to 5 tons. Nor was there any greater difficulty in making the mildest possible