the dominion of the air-第28节
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ermine how far the magnetism of the earth might be affected by height。 The solar spectrum was to be observed； air was to be collected at different heights for analysis； clouds； also upper currents； were to be reported on。 Further observations were to be made on sound； on solar radiation； on the actinic action of the sun； and on atmospheric phenomena in general。
All this must be regarded as a large order where only a very limited number of ascents were contemplated； and it may be mentioned that some of the methods of investigation； as； for instance； the use of ozone papers； would now be generally considered obsolete； while the mechanical aspiration of thermometers by a stream of air； which； as we have pointed out； was introduced by Welsh； and which is strongly insisted on at the present day； was considered unnecessary by Mr。 Glaisher in the case of wet and dry bulb hygrometers。 The entire list of instruments； as minutely described by the talented observer； numbered twenty…two articles； among which were such irreproachable items as a bottle of water and a pair of scissors。
The following is a condensed account； gathered from Mr。 Glaisher's own narrative； of his first ascent； which has been already briefly sketched in these pages by the hand of Mr。 Coxwell。 Very great difficulties were experienced in the inflation； which operation appeared as if it would never be completed； for a terrible W。S。W。 wind was constantly blowing； and the movements of the balloon were so great and so rapid that it was impossible to fix a single instrument in its position before quitting the earth； a position of affairs which； says Mr。 Glaisher； 〃was by no means cheering to a novice who had never before put his foot in the car of a balloon；〃 and when； at last； at 9。42 a。m。； Mr。 Coxwell cast off； there was no upward motion； the car simply dragging on its side till the expiration of a whole minute； when the balloon lifted； and in six minutes reached the first cloud at an altitude of 4；467 feet。 This cloud was passed at 5；802 feet； and further cloud encountered at 2；000 feet further aloft。 Four minutes later； the ascent proceeding； the sun shone out brightly； expanding the balloon into a perfect globe and displaying a magnificent view； which； however； the incipient voyager did not allow himself to enjoy until the instruments were arranged in due order； by which time a height of 10；000 feet was recorded。
Mr。 Glaisher apparently now had opportunity for observing the clouds； which he describes as very beautiful； and he records the hearing of a band of music at a height of 12；709 feet； which was attained in exactly twenty minutes from the start。 A minute later the earth was sighted through a break in the clouds； and at 16；914 feet the clouds were far below； the sky above being perfectly cloudless； and of an intense Prussian blue。
By this time Mr。 Glaisher had received his first surprise； as imparted by the record of his instruments。 At starting； the temperature of the air had stood at 59 degrees。 Then at 4；000 feet this was reduced to 45 degrees； and； further； to 26 degrees at 10；000 feet； when it remained stationary through an ascent of 3；000 feet more； during which period both travellers added to their clothing； anticipating much accession of cold。 However； at 15；500 feet the temperature had actually risen to 31 degrees； increasing to no less than 42 degrees at 19；500 feet。
Astonishing as this discovery was； it was not the end of the wonder； for two minutes later； on somewhat descending； the temperature commenced decreasing so rapidly as to show a fall of 27 degrees in 26 minutes。 As to personal experiences； Mr。 Glaisher should be left to tell his own story。 〃At the height of 18；844 feet 18 vibrations of a horizontal magnet occupied 26。8 seconds； and at the same height my pulse beat at the rate of 100 pulsations per minute。 At 19；415 feet palpitation of the heart became perceptible； the beating of the chronometer seemed very loud； and my breathing became affected。 At 19；435 feet my pulse had accelerated； and it was with increasing difficulty that I could read the instruments； the palpitation of the heart was very perceptible； the hands and lips assumed a dark bluish colour； but not the face。 At 20；238 feet 28 vibrations of a horizontal magnet occupied 43 seconds。 At 21；792 feet I experienced a feeling analogous to sea…sickness； though there was neither pitching nor rolling in the balloon； and through this illness I was unable to watch the instrument long enough to lower the temperature to get a deposit of dew。 The sky at this elevation was of a very deep blue colour； and the clouds were far below us。 At 22；357 feet I endeavoured to make the magnet vibrate； but could not； it moved through arcs of about 20 degrees； and then settled suddenly。
〃Our descent began a little after 11 a。m。； Mr。 Coxwell experiencing considerable uneasiness at our too close vicinity to the Wash。 We came down quickly from a height of 16；300 feet to one of 12；400 feet in one minute； at this elevation we entered into a dense cloud which proved to be no less than 8；000 feet in thickness and whilst passing through this the balloon was invisible from the car。 From the rapidity of the descent the balloon assumed the shape of a parachute； and though Mr。 Coxwell had reserved a large amount of ballast； which he discharged as quickly as possible； we collected so much weight by the condensation of the immense amount of vapour through which we passed that； notwithstanding all his exertions； we came to the earth with a very considerable shock； which broke nearly all the instruments。。。。 The descent took place at Langham； near Oakham。〃
Just a month later Mr。 Glaisher； bent on a yet loftier climb； made his second ascent； again under Mr。 Coxwell's guidance； and again from Wolverhampton。 Besides attending to his instruments he found leisure to make other chance notes by the way。 He was particularly struck by the beauty of masses of cloud； which； by the time 12；000 feet were reached； were far below； 〃presenting at times mountain scenes of endless variety and grandeur； while fine dome…like clouds dazzled and charmed the eye with alternations and brilliant effects of light and shade。〃
When a height of about 20；000 feet had been reached thunder was heard twice over； coming from below； though no clouds could be seen。 A height of 4；000 feet more was attained； and shortly after this Mr。 Glaisher speaks of feeling unwell。 It was difficult to obtain a deposit of dew on the hygrometer； and the working of the aspirator became troublesome。 While in this region a sound like that of loud thunder came from the sky。 Observations were practically completed at this point； and a speedy and safe return to earth was effected； the landing being at Solihull； seven miles from Birmingham。
It was on the 5th of September following that the same two colleagues carried out an exploit which will always stand alone in the history of aeronautics； namely； that of ascending to an altitude which； based on the best estimate they were able to make； they calculated to be no less than seven miles。 Whatever error may have unavoidably come into the actual estimate； which is to some extent conjectural； is in reality a small matter； not the least affecting the fact that the feat in itself will probably remain without a parallel of its kind。 In these days； when aeronauts attempt to reach an exceptionally lofty altitude； they invariably provide themselves with a cylinder of oxygen gas to meet the special emergencies of the situation； so that when regions of such attenuated air are reached that the action of heart and lungs becomes seriously affected； it is still within their power to inhale the life…giving gas which affords the greatest available restorative to their energies。 Forty years ago； however； cylinders of compressed oxygen gas were not available； and on this account alone we may state without hesitation that the enterprise which follows stands unparalleled at the present hour。
The filling station at Wolverhampton was quitted at 1。3 p。m。； the temperature of the air being 59 degrees on the ground； and falling to 41 degrees at an altitude of 5；000 feet； directly after which a dense cloud was entered； which brought the temperature down to 36 degrees。 At this elevation the report of a gun was heard。 Here Mr。 Glaisher attempted （probably for the first time in history） to take a cloud…scape photograph； the illumination being brilliant； and the plates with which he was furnished being considered extremely sensitive。 The attempt； however； was unsuccessful。 The height of two miles was reached in 19 minutes； and here the temperature was at freezing point。 In six minutes later three miles was reached； and the thermometer was down to 18 degrees。 In another twelve minutes four miles was attained； with the thermometer recording 8 degrees； and by further discharge of sand the fifth aerial milestone was passed at 1。50 p。m。； i。e。 in 47 minutes from the start； with the thermometer 2 degrees below zero。
Mr。 Glaisher relates that up to this point he had taken observations with comfort； and experienced no trouble in respiration； whilst Mr。 Coxwell； in consequence of the exertions he had to make； was breath
