as they
are. Practically it seems the perfection of safety; nor was it to a
wheel of this character that _the_ accident happened. The only
apparent risk is that there may be some slight undiscovered flaw in
the solid steel which, under the pressure of unforeseen
circumstances, may give way. But the whole design of the wheel is to
guard against the ill-effects that would follow the snapping of a
tyre. Suppose a tyre to 'fly'--the result would be a small crack;
supposing there were two cracks, or ten cracks, the speciality of
this wheel is that not one of those pieces could come off--that the
wheel would run as well and as safely with a tyre cracked through in
a dozen places as when perfectly sound. The reason of this is that
every single quarter of an inch of the tyre is fixed irremovably to
the outer edge of the iron wheel, by the continuous dovetail, by the
continuous wedge, and by the continuous overlapping. So that under
no condition could any portion of the tyre fly off from the wheel.
Close by this wheel thus finished upon this patent process there was
an old riveted wheel which had been brought in to receive a new tyre
on the new process. This old wheel aptly illustrates the advantages
of the new one. Its tyre is fixed to the wheel by rivets or bolts
placed at regular intervals. Now, the holes made for these bolts to
some extent weaken both tyre and wheel. The bolt is liable, with
constant shaking, to wear loose. The bolt only holds a very limited
area of tyre to the wheel. If the tyre breaks in two places between
the bolts, it comes off. If a bolt breaks, or the tyre breaks at the
bolt, it flies. The tyre is, in fact, only fixed on in spots with
intervals between. The new fastening leaves no intervals, and
instead of spots is fixed everywhere. This is called the Gibson
process, and was invented by an employe of the company. Latterly
another process has partially come into vogue, particularly for
wooden wheels, which are preferred sometimes on account of their
noiselessness. By this (the Mansell) process, the tyres, which are
similar, are fastened to the wheels by two circular bands which
dovetail into the tyre, and are then bolted to the wood.

To return to the wheel--now really and substantially a wheel, but
which has still to be turned so as to run perfectly true upon the
metals--it is conveyed to the wheel lathe, and affixed to what looks
like another wheel, which is set in motion by steam-power, and
carries