imore and Ohio
Railroad,--the minute details of construction being so skilfully
arranged, that changes of temperature, oftentimes so fatal to
bridges of metal, have no hurtful effect whatever. And here, again,
is seen the distinctive American feature of adaptation or
accommodation, even in the smallest detail. Mr. Bollman does not get
savage and say, "Messieurs Heat and Cold, I can get iron enough out
of the Alleghanies to resist all the power you can bring against me!"
--but only observes, "Go on, Heat and Cold! I am not going to deal
directly with you, but indirectly, by means of an agent which will
render harmless your most violent efforts!"--or, in other words, he
interposes a short link of iron between the principal members of his
bridge, which absorbs entirely all undue strains.

It is not to be supposed from what has preceded, that the American
engineer does not know how to spend money, because he gets along
with so little, and accomplishes so much; when occasion requires, he
is lavish of his dollars, and sees no longer expense, but only the
object to be accomplished. Witness, for example, the Kingwood Tunnel,
on the Baltimore and Ohio Railroad, where for a great distance the
lining or protecting arching inside is of heavy ribs of cast iron,
--making the cost of that mile of road embracing the tunnel about a
million of dollars. Nor will the traveller who observes the
construction of the New York and Erie Railroad up the Delaware Valley,
of the Pennsylvania Central down the west slopes of the Alleghanies,
or of the Baltimore and Ohio down the slopes of Cheat River, think
for a moment that the American engineer grudges money where it is
really needed.

Stone bridges so rarely occur upon the roads of America, that they
hardly need remark. The Starucca Viaduct, by Mr. Adams, upon the New
York and Erie Railroad, and the viaduct over the Patapsco, near the
junction of the Washington branch with the main stem of the
Baltimore and Ohio Railroad, show that our engineers are not at all
behind those of Europe in this branch of engineering. From the civil
let us pass to the mechanical department of railroad engineering.
This latter embraces all the machinery, both fixed and rolling;
locomotives and cars coming under the latter,--and the shop-machines,
lathes, planers, and boring-machines, forging, cutting, punching,
rolling, and shearing engines, pumps and pumping-engines for the
water-stations, turn-tables, and the like,