New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1851-02-04

paddles their diminished velocity.
To translate mathematical demonstrations into
language Ineligible to all and still absolutely
elusive is not an easy task. / may, nevertheless,
entreat those Of my readers who may happen to
be little conversant with agebraical calculations,
10 represent 10 themselves, in the room OF the &C
tual paddles Of the Baltic, two other paddle
wheels of the same diameter, but wider, and
therefore with larger blades th'n the present
ones. To find an equal backward resistance in
the water, the new paddles on account Of the
greater surface, DO not want so great velocity
as the former Now, as the pressure exercised,
either by the new or old paddles, is by superstition
the same, the required tension or density Of steam
in the cylinders will also be the same in either
case as, however, the new paddles revoye more
slowly than the old ones, the pistons also will
make, in a given time less number OF strokes,
and the vessel consume less steam and less coal.
So with wider paddles the Baltic could consume
less coal than she does, and still 60 at the same
velocity. This being once granted it will then
be easily admitted too, that if the Baltic should
employ, with the new wider paddles, the same
quantity Of coal she would necessarily acquire
greater speed. It. will also be easily understood
that instead Of making the paddles simply llrger
in width there will be en- advantage in making
them longer also, and increasing prOportlOnaly
the diameter of the wheels.
- With the mass of people the best and most alb
strsct reasoning has seldom any practical effect,
tunstely there is a capital fact at hand. Let US
look again at the dimensions OF the Baltic and
Asia The breadth of beam Of the former is -
feet, and across paddles 75l. This shows the
paddle wheels to be Of the joint breadth Of 3Oi
feet or l5i each A like calculation for the Asia
will show her paddles to have breadth OF lf4
feet each: only nine inches less than the former.
The diameter of wheels, in both cases, is exactly
the same-36 feet. 1t may then be said that the
paddles of both ste amers are very nearly equal.
So it is also with the other steamers Of the Col
Inns line. Is not this singular fact The power
setting the Asia in motion is 500, the power
working the others is 2200 and still the organ of
locomotion is the same Either the dimensions of
the Baltic or of the Asia are wrong. Theory
unhesitatUgly would have settled the question IN
favor Of the Asia even before seeing both at work
Practical men would not decide so promptly. But
here is the fact that the Asia capable OF carrying
a cargo little short OF that of the Baltic and with
only 500 horses, is faster than the latter with
2,200 horses. l hope, then, that even mere bust
ness men will readily acknowledge that OF the
two, it is the Baltic which has paddle wheels OF
improper dimensions
it is to be desired that they should be removed
for larger ones How much larger The larger
the better; but let them beart to the moving power
at least the same relation as in the Asia. To make
them So they should have a radius Of 30 feet in
stead of Is rs they now have,
This, of course, would require other alterations.
If the engines are capable Of safely enduring
greater pressure in the ratio Of the increased
length of the time of a revolution OF the wheels,
which think very likely to be the case, the cylln-
ders need not be changed il not, others might be
made, whose capacity shall bear to the capacity OF
the present cy finders the same ratio as the time
of revolution of the new wheels to that OF the old
ones The increasing of the diameter OF the
wheels, besides the corresponding augmentation
of surface in the paddles will have another advan
tage by partially obvistiDg an inconvenience, OF
which we have not yet spoken 1t is known that
considerable part of the effort necessary 70 move
the paddles immersed in water Is lost because OF
the obliquity of their action through the greater
part of their movement in the water. How much
this defect is compensated by having 5'eaIe[
number of paddlos depends on the degree OF
immersion. Now, as the great consumption
of coal must cause the water line to vary con-
siderably during the voyage, if the arc Of INNER
sion of the paddles be the best possible at any one
time it must be very unfavorable, either at the
beginning or toward the close of the voyage; and
this cause is also a considerable drawback IN the
useful effect OF the power employed. This neon
venience, however must be much less sensible
in the British than in the American steamers, as
the load of coal in the former is in proportion very
onsiderabIy smaller: but it will also be reduced
in the American steamers by the simple enlarge
ment of the diameter of the wheels 1t would be
reduced to q much more considerable extent by
making the axle capable of being raised or lowered
upon screws with corresponding eXtenslOitIy III
the connecting rods Such correction, which is
wanted nowhere to so great degree as in the
American transatlantic steamers, II adopted by
them, would indirectly benefit future steamers
even not adopting it, by furnishing the easiest and
surest manner of testing by experience what is
practically the best arc of immersion for paddle.
wheels.
lam very greatly mistaken if by such simple
and easy improvements, these magnificent and
powerful specimens of modern art would not gain
the end for which immense sums have been
and are so literally expended upon them, that Of
bringing two worlds nearer to each other not only
by a few hours, but by whole days AT any rate,
let the candid exposition Of my opinion not De con
sidered as a presumrtuous obtrusion, but as a
token OF the deep interest have with millions OF
other people, in the subject. FILoPANrI