Phenix gazette. [volume] (Alexandria [D.C.]) 1825-1833, 1831-06-04

considering the very unfair nature OF the tr'a.,
than could have been imagined. No danger Is
to be apprehended from the stoppase OF 'he dou.
bic or single boats, however suddenly, as they
brought themselves up almost instantaneous!v.-
II is right to explain, regard to the trial vi the
single boat, that this trial was made with
the same.horse that had previously done the eX-
pertinent in the double boat; otherwise the time
would, no doubt, have been considerably shorter.
One horse only was used in drawing, and, Tor The
first two or three miles, it was ridden by the drV'
er, heavy man, without saddle.
There can be no doubt that, If the above ex'
perimenthad been made with aproperly construct
ed twin boat, the surge or wave must have oeeh
diminished, if not entirely done away with; while
the boat would have been equally steady: we
understand that large passage boat, OF gig
shape. is at present constructing by MIR. w o'd,
of Port. Glasgow, for the Ardrossan Canal; and
that it is expected she will perform the voyage
between Paisley and Glasgow in three quarters
of an hour, carrying thirty-six passengers. AS
this boat is to be single, it has been suggested that
anv unstea,liness or crankness in the water may
be done away with by placing around the boat
and little above the water mar !, hollow cop
DER or iron tube, such as is usedtn safety boats.
In this way she would at once be brought to a
bearing, before yielding much to either side, and
AZ the same time the boat would be at once made
a safety boat
Three different results from the above exPe-
riment arc worthy attention: first, the case with
which the boats were brought up or stopped, When
moving at a high rate Of velocity; second, the
little additional labor in drawing, occasloned to
the horse when drawing the boat at this high rate,
as compared with low rate OF velocity; and
third, the apparent diminuion OF the surge or
agitation in the water, at high rate OF veloclty'
The best explanation of these matters is bv the
supposition. that at high rate OF velocity, the
flat boat rises toward the surface, and skins over
instead of cutting the water. The moment the
towing line is Stacked of, tho boat sinks to her
usual depth, and Of course brings herself up I'm.
med;ately, owing to the increased resistance OIL
the additional column of water, which she must
cut. Ga the other hand, when moving ct high
rate, and skimming near the surface OF the water,
the labor Of the horse ia diminished in proportion
to the diminution Of the column OF water dis
placed, and the wave or surge Is diminished IN
like ratio The Ardrossan Canal, is very small
barge canal, fitted for boats Of from 25 to SO tons
burthea, while the Forth and Clyde Canal Is ten
feet deep. and Of a proportional breadth. Inc
rigs, with which the above experiments were
made, belonged 10 Mr.. HuhteT, cuhue', o'"""
street, Glasgow, who fitted up the twin boats tor
the experiments in the Forth and Clyde Canal
and who is, at present, engaged in making the
model of large twin boat. fitted to carry pas
sensers and luggage on the Forth and Clyde Ca
nal. Great credit was due to Mr.. Hunter, foI
the mode in which the twin boat was fitted up
and connected"
The diminution Of wave or surge consequent
on very rapid motion through the canal, stated
to have been observed by Mr.. Grahame, the wri
ter of the account. appeared very anomalous and
contrary to all previous theory; and was. by ma
ny persons present at the experiment, considered
&c i,ip0l