The fixing of the percussion needle securely in the fuse-cap was an erstwhile stumbling-block in not a few machine shops, it being no exaggeration to say that in numerous instances at least 50 per cent. of the fuse-caps were rejected owing to the needle not being sufficiently securely fixed in the seating.
At Crewe a simple method ensuring absolute rigidity was devised, the fuse-cap being so turned in the lathe that a slightly outstanding lip was formed, which after the needle had been inserted in the recess was spun or pressed, whilst revolving in a turret lathe, round the taper profile of the needle, the metal being in this way packed so closely and tightly all round that the protruding end of the needle, if subsequently gripped in a vice, would sooner break off than allow itself to be extracted or even disturbed in the slightest degree whatever within its metal bedding. "Solid as a rock" is the only description applicable.
In spite of this, however, the Government either could not or would not insist on the universal adoption of so sound and simple a practice, preferring rather to standardise an entirely new method involving a more complicated and so more costly fitting, both as regards the needle itself and the fitting of it in the fuse-cap.
The cap was thenceforward drilled and tapped, and the needle which was a longer one than hitherto was screwed into the hole and joined with petman cement. Crewe, in compliance with Government specifications had perforce to toe the line, but very quickly rose to the occasion by devising an extremely neat and efficacious little tapping machine, belt driven, and reversible through the medium of a couple of hand-actuated friction clutches. The spindle of the machine ran through a guide-bush bolted to the bed of the lathe, and screwed to the pitch of the needle thread. The hole through the fuse-cap was by this means certain of being tapped to the correct pitch, without any risk of stripped or "drunken" threads ensuing. The tap itself was of a "floating" disposition; that is to say, it was held in a socket which permitted a slight amount of freedom in action, thereby ensuring perfect alignment with the fuse-cap hole.
The final operation of lacquering (or varnishing with a mixture of shellac and alcohol which imparted a saffron or orange colour to the metal and acted as a preservative) was effected by mounting the fuse on a metal disc, which, acting in conjunction with a second disc and an intermediary ball-race, was kept spinning round by hand, the operator applying the varnish with a brush the while the fuse was kept spinning.
It was noticed at one time that a fairly large percentage of shells were "duds," that is to say they were failing to explode, and the reason for this was attributed to the supposition that on being released by the plug the pellet tended to creep towards the percussion needle, thenceforward remaining closely adjacent to it, with the result that it was no longer in a position to jerk forward and strike the needle with sufficient impetus to cause a spark. An additional spring called a "creep" spring was consequently inserted, of sufficient tension to prevent the pellet from creeping forward, and yet not strong enough to prevent the sudden contact of pellet and needle, on the shell reaching its objective. This overcame the difficulty.
[CHAPTER V]
CARE OF THE CARTRIDGE CASE
"As long as war is regarded as wicked it will always have its fascinations. When it is looked upon as vulgar it will cease to attract."
Wilde.