第 54 节
作者:管他三七二十一      更新:2021-04-30 16:22      字数:9322
  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 the
  efficiency of the rudder and screw; and we put them both into
  requisition forthwith; for the purpose of altering our direction more
  to the eastward; and in a line for Paris。  By means of the rudder we
  instantly effected the necessary change of direction; and our course
  was brought nearly at right angles to that of the wind ;  when we set
  in motion the spring of the screw; and were rejoiced to find it
  propel us readily as desired。  Upon this we gave nine hearty cheers;
  and dropped in the sea a bottle; enclosing a slip of parchment with a
  brief account of the principle of the invention。  Hardly; however;
  had we done with our rejoicings; when an unforeseen accident occurred
  which discouraged us in no little degree。  The steel rod connecting
  the spring with the propeller was suddenly jerked out of place; at
  the car end; (by a swaying of the car through some movement of one of
  the two seamen we had taken up;) and in an instant hung dangling out
  of reach; from the pivot of the axis of the screw。  While we were
  endeavoring to regain it; our attention being completely absorbed; we
  became involved in a strong current of wind from the East; which bore
  us; with rapidly increasing force; towards the Atlantic。  We soon
  found ourselves driving out to sea at the rate of not less;
  certainly; than fifty or sixty miles an hour; so that we came up with
  Cape Clear; at some forty miles to our North; before we had secured
  the rod; and had time to think what we were about。  It was now that
  Mr。 Ainsworth made an extraordinary; but to my fancy; a by no means
  unreasonable or chimerical proposition; in which he was instantly
  seconded by Mr。 Holland … viz。:  that we should take advantage of the
  strong gale which bore us on; and in place of beating back to Paris;
  make an attempt to reach the coast of North America。  After slight
  reflection I gave a willing assent to this bold proposition; which
  (strange to say) met with objection from the two seamen only。  As the
  stronger party; however; we overruled their fears; and kept