Graze-fuses (so called from the fact that the very slightest touch or shock imparted to the fuse or foremost part of the shell by any intervening object, and against which the fuse grazes whilst in flight, is sufficient to cause the spark necessary for igniting the explosive charge) were first taken in hand at Crewe in March, 1915.

It was at this time that the late Earl Kitchener, then Minister of War, first drew attention in the House of Lords to the alarming position, generally, in regard to munitions of war, "I can only say (cp. the Times, March 15th, 1915) that the supply of war material at the present moment, and for the next two or three months, is causing me very serious anxiety." The persistent inconsistency of the "talking men" may here well be exemplified by the fact that in the following month of April, Mr. Asquith promptly retorted in the House of Commons that he had "seen a statement the other day that the operations, not only of our Army, but of our Allies, were being crippled or at any rate hampered, by our failure to provide the necessary ammunition. There is not a word of truth in that statement." However, as if to give an irrefutable dÉmenti to this assertion, it was only a month later that there came the sensational exposÉ from the pen of the Times military correspondent at the front, who wrote to the effect that "the want of unlimited supply of high-explosive was a fatal bar to our success" in the offensive operations round Ypres. Per contra it was pointed out from the same source that "by dint of expenditure of 276 rounds of high explosive per gun in one day, the French levelled all the enemy defences to the ground."

Hence it came about that, emanating from a modest little side-show claiming the energies of one or two apprentices and a few highly-skilled and highly-paid mechanics, the manufacture of graze-fuses developed into quite an industrial main-offensive (destined within the space of a few weeks from its inception to be entrusted to a bevy of local beauty, which became augmented as time went on in proportion as the seriousness of the military situation became apparent), pushed forward with a zeal and enthusiasm worthy of the highest praise, as the supply of shells and consequently of fuses fell hundreds per cent. short of the demand.

Trim in their neat attire of light twill cap and overall, with a not infrequent hint of black silk "open-work" veiled beneath, the ladies (God bless 'em), no sooner enlisted, lost no time in adapting themselves in a remarkable manner to the exigencies of their new surroundings. In some respects, certainly—

but however that may be, in respect at least of the manufacture of munitions of war the girls in Crewe Works showed themselves, not only amenable to reason and discipline, but became regular enthusiasts in the work on which they were engaged. Idling and indifference were qualities unknown, patience and perseverance became personified, and thanks to a highly efficient and praiseworthy organisation, coupled with a system of three consecutive eight-hour shifts, the output of fuses rapidly rose from a mere 150 per week to as many as 4000, or a steady weekly average of 3000, finally reaching a grand total of 250,000 on the cessation of hostilities.

A portion of the locomotive stores department, comprising an upper storey of the old works' fitting shop, familiarly known as the top shop—that one-time nursery of juvenile and maybe aspiring apprentices, many of whom have blossomed forth into full-blown engineers occupying positions of prominence in the four corners of the globe—was speedily transformed. Overhead shafting was fixed; lathes, drilling and tapping machines, and benches were lined up in positions convenient for the quick transition of the fuses, and their tiny components, passing in regular sequence through the many operations necessary for their fashioning.

The graze-fuse itself is an intricate and cleverly thought-out little piece of mechanism, demanding a degree of accuracy in machining such as one might reasonably have assumed would suffice to baffle even the most knowing and perspicacious little minds attributable to the fair sex. The requisite delicacy of touch may perhaps be exemplified by the fact that the pellet plug flash-hole must be drilled dead-true to a depth of almost an inch with a drill no bigger than ·062, or 1/16 of an inch.

Mr. Lloyd George, when addressing the House of Commons in June, 1915, in his capacity of Minister of Munitions, held up a fuse for members to see. "This," he said, "is one of the greatest difficulties of all in the turning-out of shells. It is one of the most intricate and beautiful pieces of machinery—before it explodes, (laughter). It indeed is supposed to be simple, but it takes 100 different gauges to turn it out."

It was not, however, quite so much a question of the number of gauges required (considerable though the above-quoted figure may sound to those uninitiated in the art of fuse-making) as of the minuteness of the limits or tolerances allowed in the manufacture of these gauges.

Some reference to, or explanation of, gauge-making will be found on a later page, so that it may perhaps here be sufficient to remark en passant that whereas in the case of shell-body gauging, tolerances ran into fractions approximating 10/1000 parts of an inch, those of fuse-gauging were of an infinitely more exacting nature, being measured in fractions so minute as 3/1000 parts of an inch.

Since the ultimate success or failure of the entire shell depended to a very great extent on the combined and unfailing action, or lightning series of movements, of the tiny internal component parts of the fuse (action which was initiated by the motion of the shell itself), the raison d'Être of dimensions measured in infinitesimal fractions of an inch becomes somewhat more apparent. The beauty of this little piece of mechanism is illustrated to some extent by the fact that it can be assembled or put together complete with its tiny internal components to the number of 10 or 12 all told, in less than a minute.

Cast in bars of brass, sections of the length required for each fuse body are cut off, and drop-forged, the probability of blow-holes being by this method eliminated as far as possible.

For the various machining operations, such as turning, boring and screwing, drilling, automatic and turret lathes played a prominent part, whilst an eminently suitable machine known as a "Sipp three-spindle drill" to which were fixed special jigs, designed for the purpose, was extensively used for the numerous small holes required.

Grooves were turned on a turret lathe round the taper-nose, these affording a grip for the fingers, when lifting the fuses out of the boxes in which they were supplied.

Briefly, the mechanical action of the graze-fuse is regulated on the following lines: A central pellet which creates the igniting spark by striking the percussion needle, is held in position by a tiny plug, which in turn is secured by a ball-headed pin, called the detent, kept in place by a spring. On the gun being fired the sudden forward impetus of the shell causes the detent pin to exert a backward pressure of 8-1/2 lbs. on the spring, this being sufficient to enable the detent pin to withdraw itself from the plug controlling the ignition pellet.

The motion of the shell once launched in flight is rotary or centrifugal, with the result that the pellet-plug flies outward, leaving the pellet itself free to strike the percussion needle the moment the fuse-nose hits or grazes the first intervening object.

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.