- 1826. | Letter on Affairs in general. 641 
four story widow, get up, after lying stunned for a moment, unhurt, and 
run away; an ox or a horse would be dashed to pieces by one-half the 
same concussion. I doubt whether it would be possible to construct 
such an extent of tunnel, or cylinder, as M. Vallance’s plan would re- 
quire, with all its appliances, air tight, or to contrive any air pumps 
which should have the power of exhausting it. But, even independent 
of this grand difficulty, and without entering into minute details, 
there remain such manifold objections to the possible success of the 
project, as would seem to make the wasting even a thought upon it 
almost a lunacy. : 
» For, in the first place, this cylinder, through which Mr. Vallance 
means to project us, I understand to be described as a sort of above, 
ground tunnel, built of brick ; about ten feet high, or thirty feet in the 
arch over. 
‘ Now, in the mere preliminary ‘step of lighting an avenue like this, 
some difficulty would arise. For though the projector treats it as capable 
of being done either by lamps or by windows, I do not find either one or 
the other plan very satisfactory. For amps would be extinguished by the 
process of exhausting the air within the tunnel, which is performed prior 
to the admission of the coach full of travellersand of the fresh stream 
of air from without, which is to sustain them. And, for glass windows, they 
would be but a ticklish holding, in a situation where the breaking of a single 
pane—from accident or malice—by destroying the air-tight quality of the 
_ eylinder, would put the whole machinery, in a moment, to a stand-still, and 
: 
leave the passengers by his Majesty’s mail stuck fast in the middle of his 
Majesty’s tunnel, without being able to get backwards or forwards! 
But I leave this difficulty—though I do not see how it is to be got over : 
—and I leave the further difficulty, of dividing the tunnel, ‘so that persons 
should be enabled to take part of a journey to Edinburgh—say to York 
—who did not want to be shot all the way ;—and I leave the already touch- 
ed upon improbabilities of making (and keeping) sucha tunnel ever air-tight 
—and of exhausting it—and of finding any wheels, or machinery, to run 
in it, which would endure the prodigious strain of a velocity even of 
fifty miles an hour:—and, supposing all these feats to be achieved, 
and the conveyance to be ready to start—-Who is there, I wish to 
know, in his senses, that would ever be prevailed upon to ride by it ? 
* A close tunnel to move through—something in appearance like a 
sewer built above ground. Just wide enough to admit a box,’ which 
is to be projected almost at the same rate that it might be thrown 
forward by gunpowder—and I am not at all sure that gunpowder 
might not actually be employed, just as conveniently as the power pro- 
posed, to effect the same purpose. An impulse from which, when we 
are once committed to it, it becomes impossible to escape. A road on 
which it is impossible to receive—or even to call for—the slightest assis- 
tance. And a velocity, under which the slightest check—the smallest 
flaw in the machinery—or oversight in the general arrangement—must , 
involve ‘every soul concerned in instantaneous and inevitable destruction ! 
One would think that nothing but the fondness of every human creature 
for his own project, could induce any man to expend either. his rnoney 
or his attention on such a scheme! 
‘And yet these objections are but a small part of those which stand in the 
way of Mr. Vallance’s possible success. He speaks of the “ prodigious im- 
provements” effected already, within the last fifty ycars, upon travelling ; 
M.M. New Series —Vov-Il. No.12. 4.N 
