and measurement which may be carried each way; and the
allowance for short weight or oversize.'

There is a boldness, a straightforwardness, an honesty in this
challenge, which cannot be mistaken. It is difficult to be interpreted
in any other sense than that the challengers _mean_ what they say.
Brother Jonathan has fairly thrown down the gauntlet to the
Britishers, and it behoves the latter to take it up in a becoming
spirit. Our ship-builders, especially on the Dee, the Clyde, the Wear,
the Mersey, and the Thames, ought to feel that much is now expected
from them; for if once the Yankees obtain a reputation--a European
reputation it will then be--for outstripping British ships on the
broad seas, our ship-owners will assuredly feel the effects in a
commercial sense.

This question of the speed of ships is a very curious one. Empirical
rules, rather than scientific principles, have hitherto determined the
forms which shall be given to ships. Smith adopts a certain form
because Brown's ship sailed well, whereas Jones's differently shaped
vessel was a bad sailer; although Smith, Brown, and Jones collectively
may be little able to shew _why_ one of the vessels should sail better
than the other.

If opportunity should occur to the reader to visit a large
ship-building establishment, such as those on any one of the five
rivers named above, he will see something like the following routine
of operation going on:--

There is, first, the 'ship's draughtsman,' whose duties are somewhat
analogous to those of the architect of a house, or the engineer of a
railway, or the scientific cutter at a fashionable tailor's: he has to
shape the materials out of which the structure is to be built up, or
at least he has to shew others how it is to be done. When the
ship-builder has received an order, we will say, to construct a ship,
and has ascertained for what route, and for what purpose, and of what
size it is to be, he and his ship's draughtsman 'lay their heads
together' to devise such an arrangement of timbers as will meet the
requirements of the case. Here it is that a _science_ of ship-building
would be valuable; the practical rules followed are deductions not so
much from general principles as from accumulated facts which are
waiting to be systematised; and until this process has been carried
further, ship-building will be an _art_, but not a _science_. Well,
then; the draughtsman, gathering up all the crumbs of knowledge
obtai