The Sun.
London, England, 1829-04-17 00:00:00

STEAM NAVIGATION EXTENDED,
AND MADE PROFITABLE.
BY CAPTAIN WICONOCHIE, ROYAL NAVY.

The great objections to the present mode of ar
plying steam to navigation are its inordinate expense,
and the little stowage left for goods, even in the
largest steam-boats. And the consequences of the
two circumstances are, that these vessels are only
used as packets—and if not improved on, will pro-
bably be, at no distant period, laid aside, for they
noNhere yield a profitable return. The following
considerations then are deemed important, as bear.
ing directly on these points.
hick
I. A mere abatement in the speed at W
steam-boats are usually impelled would be prod":
tive of great economy. The resistance to a re'
sel's passing through the water, and the expence
at which that resistance is overcome, increase
nearly as the cube of the speed gained : and duoh,
after a good medium pace is obtained, an addi-
tion to it can only be purchased at a most extra-
vagant cost. The following table illustrates this
very strikingly. It gives the powers by which a re!'
sel can be impelled at the several velocities.
3 Miles per Hour, 54- Horses.

4 -- 13
5 25
6
7 69
8
9
10
2. As steam-boats, however, are at present fit"
they can take little or no advantage of the above
principle. Their power is invariable, or nearly 5°
—one large engine, or two made to work together'
and thus, to every practical purpose, one. At a
given pace, however, the resistance will vary fror°
hour to hour with the weather, and the power should
vary too. Steam-boats sought to be worked ec°'
nomically should be fitted with three or four smith
powers, arranged so that one or more may be or
plied, precisely as required; and thus favourable cir-
cumstances would give a saving, as adverse ones
must always cause expence.
Lastly. Steam-boats in which economy is studied,
should tow, not carry. The machinery of a steam-
engine takes up so much room, that the remaining
capacity, however filled, can never defray the ex"
pence, or yield any return ; and, besides this, there
appears to be something in the principle of traction
favourable, wherever it is applied, to the transport
of heavy burthens. A horse will draw more than
he will carry. A loco-motive engine, of only eight'
horse power, drags ninety tons after it, and cannot
stir with even a half of that weight above it. It has
been ascertained in rivet-navigation, that one-third
of the power will track a vessel, at a given rate,
against the stream, that is necessary to impel her at
the same rate, if embarked on board. And every
seaman who has sent his boat a-head to tow in a
calm, must have been sensible that the same novre.f
employed on board, would not have produced the
same effect. There are two ways, however, in whirl'
this principle may be applied.
Where voyages are long, and' the sea-room is
abundant, it does not appear advantageous to emPl"Yi
steam at all, as the only, or even as the princiPa
moving power. Vessels on such services are gene'
rally large; and large steam-vessels labour under this
disadvantage,—whatever their power, the fulcrum
against which it acts is merely the water opposed t°
their paddles, and these cannot be enlarged in al
thing like the proportion in which the weight ana
resistance of a large vessel rise above those of
small. But moreover, wind costs nothing; and, °:
a large stretch, the balance of chances is so much ',
favour of a sailing-vessel's progress, from the speed
with which a fair wind impels her, and the greater
number of points of the compass which give a fair
than a foul wind, that not much is to be gained by
the punctuality of steam. (The Enterprise, for ex-
ample, was three days longer on her passage to India,
than a trader, the Betsy, from Bordeaux, which
sailed about the same time.) Still, if some aid could
be thus procured, to meet occasions of long-Pro'
tracted calm, or to assist a ship's boats when ern'
ployed under unfavourable. circumstances, it would
seem of great importance; and this would be al."-,
tually obtained by each ship's embarking a small
power, say of two, four, six, or eight horses, accord-
ing to her size, together with a boat fitted to receive
it, employing them in towing, as required. And
such an addition to a ship's stores would, in fact, be
repaid in a single voyage to one bound within the
Tropics, where calms are frequent, and boat-serhvieree
severe. And would be equal to an insurance "Tea--,1
the navigation is intricate, and the importance 01
to
occasional tug in light weather, or of being able thy
lay out an anchor at short notice, is conseque'
great,;—this last being an operation, by the waY, e,d
which, more than any other, the fate of a ship 81.„t
cargo will frequently depend, and which is Y-t
scarcely practicable at all, at present, for mercha"
vessels, unless in very favourable circumstances'
from their scant of hands.
In river or coasting navigation, however, or where
the voyages are otherwise short, and the navir
tion is confined, a more complete form of the sYS'd
tern would seem infinitely better. Strong a"
powerful, but not large steam-boats, should vesselsnl'
ployed in towing, from port to port, small s
without reular masts, but p ossessed of the means
ot
o m
f stepping
ake a g
little ju r yrasaaisti. These
s when it
vesselsmay
h
appear
av idogesirab
tholds clear fore and aft, would carry very large
cargoes for their size. They would be equally Punc-
tual and secure, deeply laden, and flying liglit.
They could have most comfortable cabins on deck!,
and thus carry passengers, as well as goods; yet tri
being entirely dependent on passengers, they worisut
not be obliged to lay by every winter, as mull
steam-packets now do. The steam-power wool
thus work the whole year for its owner, instead
the half only : besides which, it would not be de"
tamed at the end of every short voyage, unloadinf
and loading again : but, with a fresh supply of hie
would be immediately ready to proceed with another
vessel. And there can be no doubt that if worked,
besides this, us above suggested with regard t°
speed and command of power, a coasting trait,
could be thus maintained even more cheaply and
safely than by sails, and much more conveniently-
(See on this head, howeier, a paper " On the most
effective Employment of Steam-power in Navigal
tion2,—Edinburgh New Philosophical Journal
April, 1829.)
This then is the system of steam navigation Po'
posed; and so obvious, and, it may be said, unques-
tionable are the general principles on which it is
founded, that, perhaps, it might be safely left to rest
on their merits alone. If the benefits arising frl
the use of steam in navigation, are to be extende"4.
or even maintained, it must, in some way, Ile t"( 1 e
to pay, which it nowhere does pow ; and ecoValf
in its application must therefore be a first object et
study---not be systematically disregarded. A grea
effect must accordingly be sought from small pave
rs'
not a small effect from great powers. A reductil°
of speed to a medium, and the use of a variubl
power to meet a varying resistance, are pbYir°,,,
methods to attain this end. And the substitutin
of towing for carrying, seems to be at sea precisely,
what the transition from the pack-saddle to tb_
wheel-carriage was ashore, without roads to cut, °`
hills to climb, and with some other advantages Pei
culiar to itself—in particular with an actual hold
the water, by means of the steam-paddles, tp
used as a fulcrum against which to act iwhere
loco-motive engines, and it may he saig horses als°'
have for this purpose only the friction arising fr°ol
their own weight. The best and most popular a::
gument, however, in favour of any system, is t"
practical one showing the value and extent of its or
plications; and a very few of these will therefore
' now be noticed.
' 1. The steam-launches proposed, would seem Pe;
culiarly advantageous in the navy. The engir
thus embarked in a u hole fleet might frequently
contribute most essentially to cut off the rear of
flying enemy, by being all attached to a few leading
ships. In calm weather they might also withdraw
detached ships from under a heavy battery, when