make the sound work that was needed, especially when that soundness
was required in shafts, and in other pieces which, in those days, were
looked upon as of magnitude; which, indeed, they were, relatively to
the tools which could be brought to operate upon them. The
boiler-maker in his work had to trust almost entirely to the eye for
correctness of form and for regularity of punching, while all parts of
engines and machines which could not be dealt with in the lathe, in
the drilling, or in the screwing machine, had to be prepared by the
use of the chisel and the file.

At the present day, the turning and fitting shops are furnished not
only with the slide lathe, self acting in both directions, and
screw-cutting, the drilling-machine, and the screwing machine, but
with planing machines competent to plane horizontally, vertically, or
at an angle; shaping machines, rapidly reciprocating, and dealing with
almost any form of work; nut shaping machines, slot drilling
machines, and slotting machines, while the drills have become multiple
and radial; and the accuracy of the work is insured by testing on
large surface plates, and by the employment of Whitworth internal and
external standard gauges.

The boiler maker's tools now comprise the steam, compressed air,
hydraulic or other mechanical riveter, rolls for the bending of plates
while cold into the needed cylindrical or conical forms, multiple
drills for the drilling of rivet holes, planing machines to plane the
edges of the plates, ingenious apparatus for flanging them, thereby
dispensing with one row of rivets out of two, and roller expanders for
expanding the tubes in locomotive and in marine boilers; while the
punching press, where still used, is improved so as to make the holes
for seams of rivets in a perfect line, and with absolute accuracy of