the works of edgar allan poe-1-第44章
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〃This model (which; through want of time; we have necessarily
described in an imperfect manner;) was put in action at the Adelaide
Gallery; where it accomplished a velocity of five miles per hour;
although; strange to say; it excited very little interest in
comparison with the previous complex machine of Mr。 Henson … so
resolute is the world to despise anything which carries with it an
air of simplicity。 To accomplish the great desideratum of 鎟ial
navigation; it was very generally supposed that some exceedingly
complicated application must be made of some unusually profound
principle in dynamics。
〃So well satisfied; however; was Mr。 Mason of the ultimate
success of his invention; that he determined to construct
immediately; if possible; a balloon of sufficient capacity to test
the question by a voyage of some extent … the original design being
to cross the British Channel; as before; in the Nassau balloon。 To
carry out his views; he solicited and obtained the patronage of Sir
Everard Bringhurst and Mr。 Osborne; two gentlemen well known for
scientific acquirement; and especially for the interest they have
exhibited in the progress of 鎟ostation。 The project; at the desire
of Mr。 Osborne; was kept a profound secret from the public … the only
persons entrusted with the design being those actually engaged in the
construction of the machine; which was built (under the
superintendence of Mr。 Mason; Mr。 Holland; Sir Everard Bringhurst;
and Mr。 Osborne;) at the seat of the latter gentleman near
Penstruthal; in Wales。 Mr。 Henson; accompanied by his friend Mr。
Ainsworth; was admitted to a private view of the balloon; on Saturday
last … when the two gentlemen made final arrangements to be included
in the adventure。 We are not informed for what reason the two seamen
were also included in the party … but; in the course of a day or two;
we shall put our readers in possession of the minutest particulars
respecting this extraordinary voyage。
〃The balloon is composed of silk; varnished with the liquid gum
caoutchouc。 It is of vast dimensions; containing more than 40;000
cubic feet of gas ; but as coal gas was employed in place of the
more expensive and inconvenient hydrogen; the supporting power of the
machine; when fully inflated; and immediately after inflation; is not
more than about 2500 pounds。 The coal gas is not only much less
costly; but is easily procured and managed。
〃For its introduction into common use for purposes of
aerostation; we are indebted to Mr。 Charles Green。 Up to his
discovery; the process of inflation was not only exceedingly
expensive; but uncertain。 Two; and even three days; have frequently
been wasted in futile attempts to procure a sufficiency of hydrogen
to fill a balloon; from which it had great tendency to escape; owing
to its extreme subtlety; and its affinity for the surrounding
atmosphere。 In a balloon sufficiently perfect to retain its contents
of coal…gas unaltered; in quantity or amount; for six months; an
equal quantity of hydrogen could not be maintained in equal purity
for six weeks。
〃The supporting power being estimated at 2500 pounds; and the
united weights of the party amounting only to about 1200; there was
left a surplus of 1300; of which again 1200 was exhausted by ballast;
arranged in bags of different sizes; with their respective weights
marked upon them … by cordage; barometers; telescopes; barrels
containing provision for a fortnight; water…casks; cloaks;
carpet…bags; and various other indispensable matters; including a
coffee…warmer; contrived for warming coffee by means of slack…lime;
so as to dispense altogether with fire; if it should be judged
prudent to do so。 All these articles; with the exception of the
ballast; and a few trifles; were suspended from the hoop overhead。
The car is much smaller and lighter; in proportion; than the one
appended to the model。 It is formed of a light wicker; and is
wonderfully strong; for so frail looking a machine。 Its rim is about
four feet deep。 The rudder is also very much larger; in proportion;
than that of the model ; and the screw is considerably smaller。 The
balloon is furnished besides with a grapnel; and a guide…rope ;
which latter is of the most indispensable importance。 A few words; in
explanation; will here be necessary for such of our readers as are
not conversant with the details of aerostation。
〃As soon as the balloon quits the earth; it is subjected to the
influence of many circumstances tending to create a difference in its
weight ; augmenting or diminishing its ascending power。 For
example; there may be a deposition of dew upon the silk; to the
extent; even; of several hundred pounds ; ballast has then to be
thrown out; or the machine may descend。 This ballast being
discarded; and a clear sunshine evaporating the dew; and at the same
time expanding the gas in the silk; the whole will again rapidly
ascend。 To check this ascent; the only recourse is; (or rather
_was_; until Mr。 Green's invention of the guide…rope;) the permission
of the escape of gas from the valve ; but; in the loss of gas; is a
proportionate general loss of ascending power ; so that; in a
comparatively brief period; the best…constructed balloon must
necessarily exhaust all its resources; and come to the earth。 This
was the great obstacle to voyages of length。
〃The guide…rope remedies the difficulty in the simplest manner
conceivable。 It is merely a very long rope which is suffered to
trail from the car; and the effect of which is to prevent the balloon
from changing its level in any material degree。 If; for example;
there should be a deposition of moisture upon the silk; and the
machine begins to descend in consequence; there will be no necessity
for discharging ballast to remedy the increase of weight; for it is
remedied; or counteracted; in an exactly just proportion; by the
deposit on the ground of just so much of the end of the rope as is
necessary。 If; on the other hand; any circumstances should cause
undue levity; and consequent ascent; this levity is immediately
counteracted by the additional weight of rope upraised from the
earth。 Thus; the balloon can neither ascend or descend; except
within very narrow limits; and its resources; either in gas or
ballast; remain comparatively unimpaired。 When passing over an
expanse of water; it becomes necessary to employ small kegs of copper
or wood; filled with liquid ballast of a lighter nature than water。
These float; and serve all the purposes of a mere rope on land。
Another most important office of the guide…rope; is to point out the
_direction_ of the balloon。 The rope _drags_; either on land or sea;
while the balloon is free ; the latter; consequently; is always in
advance; when any progress whatever is made : a comparison;
therefore; by means of the compass; of the relative positions of the
two objects; will always indicate the _course_。 In the same way; the
angle formed by the rope with the vertical axis of the machine;
indicates the _velocity_。 When there is _no_ angle … in other words;
when the rope hangs perpendicularly; the whole apparatus is
stationary ; but the larger the angle; that is to say; the farther
the balloon precedes the end of the rope; the greater the velocity ;
and the converse。
〃As the original design was to cross the British Channel; and
alight as near Paris as possible; the voyagers had taken the
precaution to prepare themselves with passports directed to all parts
of the Continent; specifying the nature of the expedition; as in the
case of the Nassau voyage; and entitling the adventurers to exemption
from the usual formalities of office : unexpected events; however;
rendered these passports superfluous。
〃The inflation was commenced very quietly at daybreak; on
Saturday morning; the 6th instant; in the Court…Yard of Weal…Vor
House; Mr。 Osborne's seat; about a mile from Penstruthal; in North
Wales ; and at 7 minutes past 11; every thing being ready for
departure; the balloon was set free; rising gently but steadily; in a
direction nearly South ; no use being made; for the first half hour;
of either the screw or the rudder。 We proceed now with the journal;
as transcribed by Mr。 Forsyth from the joint MSS。 Of Mr。 Monck
Mason; and Mr。 Ainsworth。 The body of the journal; as given; is in
the hand…writing of Mr。 Mason; and a P。 S。 is appended; each day;
by Mr。 Ainsworth; who has in preparation; and will shortly give the
public a more minute; and no doubt; a thrillingly interesting account
of the voyage。
〃THE JOURNAL。
〃_Saturday; April the 6th_。 … Every preparation likely to
embarrass us; having been made over night; we commenced the inflation
this morning at daybreak ; but owing to a thick fog; which
encumbered the folds of the silk and rendered it unmanageable; we did
not get through before nearly eleven o'clock。 Cut loose; then; in
high spirits; and rose gently but steadily; with a light breeze at
North; which bore us in the direction of the British Channel。 Found
the ascending force greater than we had expected ; and as we arose
higher and so got clear of the cliffs; and more in the sun's rays;
our ascent became very rapid。 I did not wish; however; to lose gas
at so early a period of the adventure; and so concluded to ascend for
the present。 We soon ran out our guide…rope ; but even when we had
raised it clear of the earth; we still went up very rapidly。 The
balloon was unusually steady; and looked beautifully。 In about ten
minutes after starting; the barometer indicated an altitude of 15;000
feet。 The weather was remarkably fine; and the view of the subjacent
country … a most romantic one when seen from any point; … was now
especially sublime。 The numerous deep gorges presented the appearance
of lakes; on account of the dense vapors with which they were filled;
and the pinnacles and crags to the South East; piled in inextricable
confusion; resembling nothing so much as the giant cities of eastern
fable。 We were rapidly approaching the mountains in the South ; but
our elevation was more than sufficient to enable us to pass them in
safety。 In a few minutes we soared over them in fine style ; and
Mr。 Ainsworth; with the seamen; was surprised at their apparent want
of altitude when viewed from the car; the tendency of great elevation
in a balloon being to reduce inequalities of the surface below; to
nearly a dead level。 At half…past eleven still proceeding nearly
South; we obtained our first view of the Bristol Channel ; and; in
fifteen minutes afterward; the line of breakers on the coast appeared
immediately beneath us; and we were fairly out at sea。 We now
resolved to let off enough gas to bring our guide…rope; with the
buoys affixed; into the water。 This was immediately done; and we
commenced a gradual descent。 In about twenty minutes our first buoy
dipped; and at the touch of the second soon afterwards; we remained
stationary as to elevation。 We were all now anxious to test