按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
s assistance； he was forced to rest his arms on the ring and drop down。 Even then； the table being in the way； he was unable to approach； and； feeling insensibility stealing over himself； he became anxious to open the valve。 〃But in consequence of having lost the use of his hands he could not do this。 Ultimately he succeeded by seizing the cord in his teeth and dipping his head two or three times until the balloon took a decided turn downwards。〃 Mr。 Glaisher adds that no inconvenience followed his insensibility； and presently dropping in a country where no conveyance of any kind could be obtained； he was able to walk between seven and eight miles。
The interesting question of the actual height attained is thus discussed by Mr。 Glaisher：〃I have already said that my last observation was made at a height of 29；000 feet。 At this time； 1。54 p。m。； we were ascending at the rate of 1；000 feet per minute； and when I resumed observations we were descending at the rate of 2；000 feet per minute。 These two positions must be connected； taking into account the interval of time between； namely； thirteen minutes； and on these considerations the balloon must have attained the altitude of 36；000 or 37；000 feet。 Again； a very delicate minimum thermometer read minus 11。9； and this would give a height of 37；000 feet。 Mr。 Coxwell； on coming from the ring； noticed that the centre of the aneroid barometer； its blue hand； and a rope attached to the car； were all in the same straight line； and this gave a reading of seven inches； and leads to the same result。 Therefore； these independent means all lead to about the same elevation； namely； fully seven miles。〃
So far we have followed Mr。 Glaisher's account only； but Mr。 Coxwell has added testimony of his own to this remarkable adventure； which renders the narrative more complete。 He speaks of the continued rotation of the balloon and the necessity for mounting into the ring to get possession of the valve line。 〃I had previously；〃 he adds； 〃taken off a thick pair of gloves so as to be the better able to manipulate the sand…bags； and the moment my unprotected hands rested on the ring； which retained the temperature of the air； I found that they were frost…bitten； but I did manage to bring down with me the valve line； after noticing the hand of the aneroid barometer； and it was not long before I succeeded in opening the shutters in the way described by Mr。 Glaisher。。。。 Again； on letting off more gas； I perceived that the lower part of the balloon was rapidly shrinking； and I heard a sighing； as if it were in the network and the ruffled surface of the cloth。 I then looked round； although it seemed advisable to let off more gas； to see if I could in any way assist Mr。 Glaisher； but the table of instruments blocked the way； and I could not； with disabled hands； pass beneath。 My last hope； then； was in seeking the restorative effects of a warmer stratum of atmosphere。。。。 Again I tugged at the valve line； taking stock； meanwhile； of the reserve ballast in store； and this； happily； was ample。
〃Never shall I forget those painful moments of doubt and suspense as to Mr。 Glaisher's fate； when no response came to my questions。 I began to fear that he would never take any more readings。 I could feel the reviving effects of a warmer temperature； and wondered that no signs of animation were noticeable。 The hand of the aneroid that I had looked at was fast moving； while the under part of the balloon had risen high above the car。 I had looked towards the earth； and felt the rush of air as it passed upwards； but was still in despair when Mr。 Glaisher gasped with a sigh； and the next moment he drew himself up and looked at me rather in confusion； and said he had been insensible； but did not seem to have any clear idea of how long until he caught up his pencil and noted the time and the reading of the instruments。〃
The descent； which was at first very rapid； was effected without difficulty at Cold Weston。
CHAPTER XV。 FURTHER SCIENTIFIC VOYAGES OF GLAISHER AND COXWELL。
Early in the following spring we find the same two aeronauts going aloft again on a scientific excursion which had a termination nearly as sensational as the last。 The ascent was from the Crystal Palace； and the intention being to make a very early start the balloon for this purpose had been partially filled overnight； but by the morning the wind blew strongly； and； though the ground current would have carried the voyagers in comparative safety to the southwest； several pilots which were dismissed became； at no great height； carried away due south。 On this account the start was delayed till 1 p。m。； by which time the sky had nearly filled in； with only occasional gleams of sun between the clouds。 It seemed as if the travellers would have to face the chance of crossing the Channel； and while； already in the car； they were actually discussing this point； their restraining rope broke； and they were launched unceremoniously into the skies。 This occasioned an unexpected lurch to the car； which threw Mr。 Glaisher among his instruments； to the immediate destruction of some of them。
Another result of this abrupt departure was a very rapid rise； which took the balloon a height of 3；000 feet in three minutes' space； and another 4；000 feet higher in six minutes more。 Seven thousand feet vertically in nine minutes is fast pace； but the voyagers were to know higher speed yet that day when the vertical motion was to be in the reverse and wrong direction。 At the height now reached they were in cloud； and while thus enveloped the temperature； as often happens； remained practically stationary at about 32 degrees； while that of the dew point increased several degrees。 But； on passing out of the cloud； the two temperatures were very suddenly separated； the latter decreasing rapidly under a deep blue upper sky that was now without a cloud。 Shortly after this the temperature dropped suddenly some 8 degrees； and then； during the next 12；000 feet； crept slowly down by small stages。 Presently the balloon； reaching more than twenty thousand feet； or； roughly； four miles； and still ascending； the thermometer was taken with small fits of rising and falling alternately till an altitude of 24；000 feet was recorded； at which point other and more serious matters intruded themselves。
The earth had been for a considerable time lost to view； and the rate and direction of recent progress had become merely conjectural。 What might be taking place in these obscured and lofty regions？ It would be as well to discover。 So the valve was opened rather freely； with the result that the balloon dropped a mile in three minutes。 Then another mile slower； by a shade。 Then at 12；000 feet a cloud layer was reached； and shortly after the voyagers broke through into the clear below。
At that moment Mr。 Glaisher； who was busy with his instruments； heard Mr。 Coxwell make an exclamation which caused him to look over the car； and he writes； 〃The sea seemed to be under us。 Mr。 Coxwell again exclaimed； 'There's not a moment to spare： we must save the land at all risks。 Leave the instruments。' Mr。 Coxwell almost hung to the valve line； and told me to do the same； and not to mind its cutting my hand。 It was a bold decision opening the valve in this way； and it was boldly carried out。〃 As may be supposed； the bold decision ended with a crash。 The whole time of descending the four and a quarter miles was a quarter of an hour； the last two miles taking four minutes only。 For all that； there was no penalty beyond a few bruises and the wrecking of the instruments； and when land was reached there was no rebound； the balloon simply lay inert hard by the margin of the sea。 This terrific experience in its salient details is strangely similar to that already recorded by Albert Smith。
In further experimental labours conducted during the summer of this year； many interesting facts stand out prominently among a voluminous mass of observations。 In an ascent in an east wind from the Crystal Palace in early July it was found that the upper limit of that wind was reached at 2；400 feet； at which level an air…stream from the north was encountered； but at 3；000 feet higher the w