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or is his arduous and unassisted task abandoned here； but with marvellous pertinacity he yet struggled upwards till a height of no less than 23；000 feet is recorded； and the thermometer had sunk to 14 degrees F。 Four miles and a quarter above the level of the sea； reached by a solitary aerial explorer； whose legitimate training lay apart from aeronautics； and whose main care was the observation of the philosophical instruments he carried！ The achievement of this French savant makes a brilliant record in the early pages of our history。
It is not surprising that Lussac should own to having felt no inconsiderable personal discomfort before his venture was over。 In spite of warm clothing he suffered greatly from cold and benumbed fingers； not less also from laboured breathing and a quickened pulse； headache supervened； and his throat became parched and unable to swallow food。 In spite of all； he conducted the descent with the utmost skill； climbing down quietly and gradually till he alighted with gentle ease at St。 Gourgen； near Rouen。 It may be mentioned here that the analysis of the samples of air which he had brought down proved them to contain the normal proportion of oxygen； and to be essentially identical； as tested in the laboratory； with the free air secured at the surface of the earth。
The sudden and apparently unaccountable variation in temperature recorded by Lussac is a striking revelation to an aerial observer； and becomes yet more marked when more sensitive instruments are used than those which were taken up on the occasion just related。 It will be recorded in a future chapter how more suitable instruments came in course of time to be devised。 It is only necessary to point out at this stage that instruments which lack due sensibility will unavoidably read too high in ascents； and too low in descents where； according to the general law； the air is found to grow constantly colder with elevation above the earth's surface。 It is strong evidence of considerable efficiency in the instruments； and of careful attention on the part of the observer； that Lussac was able to record the temporary inversion of the law of change of temperature above…mentioned。 Had he possessed modern instrumental equipment he would have brought down a yet more remarkable account of the upper regions which he visited； and learned that the variations of heat and cold were considerably more striking than he supposed。
With a specially devised instrument used with special precautions； the writer； as will be shown hereafter； has been able to prove that the temperature of the air； as traversed in the wayward course of a balloon； is probably far more variable and complex than has been recorded by most observers。
The exceptional height claimed to have been reached by Gay Lassac need not for a moment be questioned； and the fact that he did not experience the same personal inconvenience as has been complained of by mountain climbers at far less altitudes admits of ready explanation。 The physical exertion demanded of the mountaineer is entirely absent in the case of an aeronaut who is sailing at perfect ease in a free balloon。 Moreover； it must be remembered thata most important considerationthe aerial voyager； necessarily travelling with the wind； is unconscious； save at exceptional moments； of any breeze whatever； and it is a well…established fact that a degree of cold which might be insupportable when a breeze is stirring may be but little felt in dead calm。 It should also be remembered； in duly regarding Gay Lussac's remarkable record； that this was not his first experience of high altitudes； and it is an acknowledged truth that an aeronaut； especially if he be an enthusiast； quickly becomes acclimatised to his new element； and sufficiently inured to its occasional rigours。
CHAPTER V。 SOME FAMOUS EARLY VOYAGERS。
During certain years which now follow it will possibly be thought that our history； so far as incidents of special interest are concerned； somewhat languishes。 Yet it may be wrong to regard this period as one of stagnation or retrogression。
Before passing on to later annals； however； we must duly chronicle certain exceptional achievements and endeavours as yet unmentioned； which stand out prominently in the period we have been regarding as also in the advancing years of the new century Among these must in justice be included those which come into the remarkable； if somewhat pathetic subsequent career of the brilliant； intrepid Lunardi。
Compelling everywhere unbounded admiration he readily secured the means necessary for carrying out further exploits wherever he desired while at the same time he met with a measure of good fortune in freedom from misadventure such as has generally been denied to less bold adventurers。 Within a few months of the time when we left him； the popular hero and happy recipient of civic and royal favours； we find him in Scotland attempting feats which a knowledge of practical difficulties bids us regard as extraordinary。
To begin with； nothing appears more remarkable than the ease； expedition； and certainty with which in days when necessary facilities must have been far harder to come by than now； he could always fill his balloon by the usually tedious and troublesome mode attending hydrogen inflation。 We see him at his first Scottish ascent； completing the operation in little more than two hours。 It is the same later at Glasgow； where； commencing with only a portion of his apparatus； he finds the inflation actually to proceed too rapidly for his purpose； and has to hold the powers at his command strongly in check。 Later； in December weather； having still further improved his apparatus； he makes his balloon support itself after the inflation of only ten minutes。 Then； as if assured of impunity； he treats recognised risks with a species of contempt。 At Kelso he hails almost with joy the fact that the wind must carry him rapidly towards the sea； which in the end he narrowly escapes。 At Glasgow the chances of safe landing are still more against him； yet he has no hesitation in starting； and at last the catastrophe he seemed to court actually overtook him； and he plumped into the sea near Berwick； where no sail was even in sight； and a winter's night coming on。 From this predicament he was rescued by a special providence which once before had not deserted him； when in a tumult of violent and contrary currents； and at a great height to boot； his gallery was almost completely carried away； and he had to cling on to the hoop desperately with both hands。
Then we lose sight of the dauntless； light…hearted Italian for one…and…twenty years； when in the Gentleman's Magazine of July 31； 1806； appears the brief line； 〃Died in the convent of Barbadinas； of a decline； Mr。 Vincent Lunardi； the celebrated aeronaut。〃
Garnerin； of whom mention has already been made； accomplished in the summer of 1802 two aerial voyages marked by extreme velocity in the rate of travel。 The first of these is also remarkable as having been the first to fairly cross the heart of London。 Captain Snowdon； R。N。； accompanied the aeronaut。 The ascent took place from Chelsea Gardens； and proved so great an attr