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the dominion of the air-第24章

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here are occasions which must come into the experience of every zealous aeronaut when his balloon has descended in a rough wind; and in awkward country。  This may; indeed; happen even when the ascent has been made in calm。  Squalls of wind may spring up at short notice; or after traversing only two or three counties a strong gale may be found on the earth; though such was absent in the starting ground。  This is more particularly the case when the landing chances to be on high ground in the neighbourhood of the sea。  In these circumstances; the careful balloonist; who will generally be forewarned by the ruffle on any water he may pass; or by the drift of smoke; the tossing of trees; or by their very rustling or 〃singing〃 wafted upwards to him; will; if possible; seek for his landing place the lee of a wood or some other sheltered spot。  But; even with all his care; he will sometimes find himself; on reaching earth; being dragged violently across country on a mad course which the anchor cannot check。  Now; the country through which he is making an unwilling steeplechase may be difficult; or even dangerous。  Rivers; railway cuttings; or other undesirable obstacles may lie ahead; or; worse yet; such a death trap as in such circumstances almost any part of Derbyshire affords; with its stone walls; its precipitous cliffs; and deep rocky dells。  To be dragged at the speed of an express train through territory of this description will presently mean damage to something; perhaps to telegraph poles; to roofs; or crops; and if not; then to the balloon itself。  Something appertaining to it must be victimised; and it is in all ways best that this should be the fabric of the balloon itself。  If made of some form; or at least some proportion of linen; this will probably rend ere long; and; allowing the gas to escape; will soon bring itself to rest。  On the other hand; if the balloon proper is a silk one; with sound net and in good condition; it is probable that something else will give way first; and that something may prove to be the hapless passenger or passengers。

And here be it laid down as one first and all…important principle; that in any such awkward predicament as that just described; if there be more than one passenger aboard; let none attempt to get out。  In the first place; he may very probably break a limb in so doing; inasmuch as the tangle of the ropes will not allow of his getting cut readily; or; when actually on the ground; he may be caught and impaled by the anchor charging and leaping behind。  But; worse than all; he may; in any case; jeopardise the lives of his companions; who stand in need of all the available weight and help that the car contains up to the moment Of coming to final rest。

We have already touched on the early notions as to the means of steering a balloon。  Oars had been tested without satisfactory result; and the conception of a rotary screw found favour among theorists at this time; the principle being actually tried with success in working models; which; by mechanical means; could be made to flit about in the still air of the lecture room; but the only feasible method advocated was that already alluded to; which depended on the undesirable action of a trail rope dragging over the ground or through water。  The idea was; of course; perfectly practical; and was simply analogous to the method adopted by sailors; who; when floating with the stream but without wind; are desirous of gaining 〃steerage way。〃  While simply drifting with the flood; they are unable to guide their vessel in any way; and this; in practice; is commonly effected by simply propelling the vessel faster than the stream; in which case the rudder at once becomes available。  But the same result is equally well obtained by slowing the vessel; and this is easily accomplished by a cable; with a small anchor or other weight attached; dragging below the vessel。  This cable is essentially the same as the guide…rope of the older aeronauts。

It is when we come to consider the impressions and sensations described by sky voyagers of bygone times that we find them curiously at variance with our own。  As an instance; we may state that the earth; as seen from a highflying balloon; used to be almost always described as appearing concave; or like a huge basin; and ingenious attempts were made to prove mathematically that this must be so。  The laws of refraction are brought in to prove the fact; or; again; the case is stated thus:  Supposing the extreme horizon to be seen when the balloon is little more than a mile high; the range of view on all sides will then be; roughly; some eighty miles。  If; then; a line were drawn from the aerial observer to this remote distance; that line would be almost horizontal; so nearly so that he cannot persuade himself that his horizon is otherwise than still on a level with his eye; yet the earth below him lies; as it seems; at the bottom of a huge gulf。  Thus the whole visible earth appears as a vast bowl or basin。  This is extremely ingenious reasoning; and not to be disregarded; but the fact remains that in the experience of the writer and of many others whom he has consulted; there is no such optical illusion as I have just discussed; and to their vision it is impossible to regard the earth as anything but uniformly flat。

Another impression invariably insisted on by early balloonists is that the earth; on quitting it; appears to drop away into an abyss; leaving the voyagers motionless; and this illusion must; indeed; be probably universal。  It is the same illusion as the apparent gliding backwards of objects to a traveller in a railway carriage; only in this latter case the rattling and shaking of the carriage helps the mind to grasp the real fact that the motion belongs to the train itself; whereas it is otherwise with a balloon; whose motion is so perfectly smooth as to be quite imperceptible。

Old ideas; formed upon insufficient observations; even if erroneous; were slow to die。  Thus it used to be stated that an upper cloud floor adapted itself to the contour of the land over which it rested; giving what Mr。 Monck Mason has called a 〃phrenological estimate〃 of the character of the earth below; the clouds; 〃even when under the influence of rapid motion; seeming to accommodate themselves to all variations of form in the surface of the subjacent soil; rising with its prominences and sinking with its depressions。〃  Probably few aeronauts of the present time will accept the statement。

It used commonly to be asserted; and is so often to this day; that a feeling as of sea…sickness is experienced in balloon travel; and the notion has undoubtedly arisen from the circumstances attending an ascent in a captive balloon。  It were well; now that ballooning bids fair to become popular; to disabuse the public mind of such a wholly false idea。  The truth is that a balloon let up with a lengthy rope and held captive will; with a fitful breeze; pitch and sway in a manner which may induce all the unpleasant feelings attending a rough passage at sea。  It may do worse; and even be borne to earth with a puff of wind which may come unexpectedly; and considerably unsettle the nerves of any holiday passenger。  I could tell of a 〃
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