The history of the first locomotives in America. From original ...

lOCOMOTIVE-WOEKS. 233
and patterns are already in existence for every one of the parts to
be constructed, unless the engine is of a class never before built.
These drawings and patterns all have their separate distinguishing
numbers. Each order for the production of any part, or for the
finishing or fitting of it, bears also the number of the drawing or
pattern to which the work is to be done. These order-books and
necessary plans and patterns now go to the several departments,
and, with the fulfilment of the orders which they communicate,
must result all the parts required for the complete locomotive.
" Following these brders, we are led first to lihe boiler-shop.
Here the sheets of iron or steel, as the case may be, are laid out.
Both materials are now used for boilers, according to the prefer-
ence of customers. The homogeneous cast-steel manufactured in
this country, and which has come into use within the past few
years, gives a metal, for fire-boxes and boilers, which is surpassed
by no other yet used for the purpose. To the credit of American
manufacturers it may be said, moreover, that for these uses the
homogeneous cast-steel plates manufactured in the United States
are superior to any steel that can be imported. The steel plates
used for boilers are five-sixteenths, of an inch thick, iron plates are
three-eighths. The former, though thinner, give, on account of the
superior character of the metal, a tensile strength about thirty
per cent, greater than the five-eighth-inch iron plates. For the
boxes, steel has now almost entirely superseded all other metals.
For boilers, it is gradually but steadily coming into use. The
first , cost for a steel boiler is from two hundred and fifty to five
hundred dollars greater than for iron, but the superior strength
and durability of those made of steel plates fully warrant the
expenditure, in the judgment of many railroad officers.
" Before being put into a boiler, every sheet, whether of steel
or iron, is carefully tested, and the slightest flaw or imperfection
in the metal is at once detected by the expert who devotes his
whole attention to this important duty. If tried and not found
wanting, the great jaws of steam-shears cut them to the required
size; four great flange-fires then receive them, where they are
softened so as to be pressed and beaten into the proper curve j
the steam punching-machine, or the drilling-machine, as the case
may be, perforates the edges with holes of the exact size, form, and
equidistant ; then, with hammer and tongs, the sheets are tacked
together by an occasional rivet, a powerful crane takes the skeleton
up and delivers it to the steam riveting-machine, where every
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