time of Bramah arose from the tremendous pressure
exercised by the pump, which forced the water through between the solid
piston and the side of the cylinder in which it worked in such
quantities as to render the press useless for practical purposes.
Bramah himself was at first completely baffled by this difficulty. It
will be observed that the problem was to secure a joint sufficiently
free to let the piston slide up through it, and at the same time so
water-tight as to withstand the internal force of the pump. These two
conditions seemed so conflicting that Bramah was almost at his wit's
end, and for a time despaired of being able to bring the machine to a
state of practical efficiency. None but those who have occupied
themselves in the laborious and often profitless task of helping the
world to new and useful machines can have any idea of the tantalizing
anxiety which arises from the apparently petty stumbling-blocks which
for awhile impede the realization of a great idea in mechanical
invention. Such was the case with the water-tight arrangement in the
hydraulic press. In his early experiments, Bramah tried the expedient
of the ordinary stuffing-box for the purpose of securing the required
water tightness' That is, a coil of hemp on leather washers was placed
in a recess, so as to fit tightly round the moving ram or piston, and
it was further held in its place by means of a compressing collar
forced hard down by strong screws. The defect of this arrangement was,
that, even supposing the packing could be made sufficiently tight to
resist the passage of the water urged by the tremendous pressure from
beneath, such was the grip which the compressed material took of the
ram of the press, that it could not be got to return down after the
water pressure had been removed.

In this dilemma, Bramah's ever-ready workman, Henry Maudslay, came to
his rescue. The happy idea occurred to him of employing the pressure
of the water itself to give the requisite water-tightness to the
collar. It was a flash of common-sense genius--beautiful through its
very simplicity. The result was Maudslay's self-tightening collar, the
action of which a few words of description will render easily
intelligible. A collar of sound leather, the convex side upwards and
the concave downwards, was fitted into the recess turned out in the
neck of the press-cylinder, at the place formerly used as a
stuffing-box. Immediately on the high pressure w