ase with one of the shafts of
the "Leviathan," in England. So with the shafts of the new Collins'
steamer "Adriatic." They were forged in Reading, Pennsylvania, and in
addition to their enormous prime cost had to incur that of shipment
from the interior of Pennsylvania to the city of New-York. In all such
cases the prime cost increases immensely, and to an extent that would
hardly be credited by those not practically familiar with the subject.

3. Again, high or increased power and speed require more frequent and
more costly repairs. Friction arises from the pressure of two bodies
moving in opposite directions, and pressure results from the exertion
of power, and in the ratio of the power applied. The amount of
friction, therefore, is in the ratio of the power expended and of the
extra weight of parts required for that power. But the effects of
friction require a higher ratio when the power is greatly multiplied,
as in the case of high speed. An immensely heavy shaft exerting an
unusual force is certain to greatly heat the journals and boxes, and
thus wear them away far more rapidly. Also a rapid motion of heavy
parts of machinery, and the necessarily severe concussions and
jarrings can not fail destroying costly working parts in the engine,
and necessitating heavy and expensive repairs and substitutions. An
ordinary engine working at a slow and easy rate, will not require one
tenth the repairs necessary if it were working up to a high power and
accomplishing a high speed. With any little derangement the engines
can stop and the injury can be repaired before it reaches any
magnitude. But with rapid mail packets the engines must run on, and
the derangement which at first is small, will amount in the end, when
the voyage is completed and the mails are delivered, to a sum probably
ten or twenty times as great as in the case of the vessel that stops
and makes her repairs as she requires them. The exertion of a high
mail power causes many costly parts to burn out from unrelieved
pressure and friction, which would not be the case under other
conditions. It is also nearly impossible for the best built engines in
the world to make fast time without breaking some important part at
every trip or two, or so cracking and injuring it from the continued
strain, that a wise precaution requires its removal to make the
steamer perfectly sea-worthy. Every practical man knows these
difficulties, and every steamship owner estimates their i