CHAPTER IV
THE BALLOON AS A SCIENTIFIC INSTRUMENT
So far, in our history of aeronautics, we have referred to ballooning only as a sport or pastime for the amusement of spectators, and for the gratifying of a love of adventure. It is now time to speak of the practical uses of the balloon, and how it has been employed as a most valuable scientific instrument to teach us facts about the upper atmosphere, its nature and extent, the clouds, the winds and their ways, the travel of sounds, and many other things of which we should otherwise be ignorant.
Before the invention of the balloon men were quite unaware of the nature of the air even a short distance above their heads. In those days high mountain climbing had not come into fashion, and when Pilâtre de Rozier made the first ascent, it was considered very doubtful whether he might be able to exist in the strange atmosphere aloft. Charles and Roberts were the first to make scientific observations from a balloon, for they took up a thermometer and barometer, and made certain rough records, as also did other early aeronauts. The most interesting purely scientific ascents of early days, however, were made in the autumn of 1804, from Paris, by Gay Lussac, a famous French philosopher. He took up with him all manner of instruments, among them a compass (to see if the needle behaved the same as on earth), an apparatus to test the electricity of the air, thermometers, barometers, and hygrometers, carefully exhausted flasks in which to bring down samples of the upper air, birds, and even insects and frogs, to see how great heights affected them. In his second voyage his balloon attained the enormous altitude of 23,000 feet, or more than four miles and a quarter, and nearly 2000 feet higher than the highest peaks of the Andes. At this tremendous height the temperature fell to far below freezing-point, and the aeronaut became extremely cold, though warmly clad; he also felt headache, a difficulty in breathing, and his throat became so parched that he could hardly swallow. Nevertheless, undismayed by the awfulness of his position, he continued making his observations, and eventually reached the ground in safety, and none the worse for his experience.
Gay Lussac’s experiments at least proved that though the air becomes less and less dense as we ascend into it, it remains of the same nature and constitution. His second voyage also showed that the limit to which man could ascend aloft into the sky and yet live had not yet been reached. Almost sixty years later other scientific ascents threw fresh light on this point, and also continued the other investigations that Gay Lussac had commenced.
Towards the close of Charles Green’s famous career, scientific men in England woke up to the fact that the use of a balloon as an important means for obtaining observations on meteorology and other matters had of late been very much neglected. The British Association took the matter up, and provided the money for four scientific ascents, which were made by Mr. Welsh of Kew Observatory, a trained observer. Green was the aeronaut chosen to accompany him, and the balloon used was none other than the great Nassau balloon, of whose many and wonderful adventures we have already spoken. Green was then nearly seventy years of age, but his skill as an aeronaut was as great as ever, and Welsh was able to obtain many valuable records. During the last voyage a height was attained almost as great as that reached by Gay Lussac, and both men found much difficulty in breathing. While at this elevation they suddenly noticed they were rapidly approaching the sea, and so were forced to make a very hasty descent, in which many of the instruments were broken.
The veteran Green lived to a ripe old age, dying in 1870, aged eighty-five. When a very old man he still delighted in taking visitors to an outhouse where he kept the old Nassau balloon, now worn out and useless, and, handling it affectionately, would talk of its famous adventures and his own thousand ascents, during which he had never once met with serious accident or failure. After his death the old balloon passed into the hands of another equally famous man, who, after Green’s retirement, took his place as the most celebrated English aeronaut of the day.
This was Henry Coxwell. He was the son of a naval officer, and was brought up to the profession of a dentist. But when a boy of only nine years old he watched, through his father’s telescope, a balloon ascent by Green, which so fired his imagination that henceforward balloons filled all his thoughts. As he grew older the fascination increased upon him. He would go long distances to see ascents or catch glimpses of balloons in the air, and he was fortunate enough to be present at the first launching of the great Nassau balloon. He did not get the chance of a voyage aloft, however, till he was twenty-five; but after this nothing could restrain his ardour, and, throwing his profession to the winds, he made ascent after ascent on all possible occasions.
In one of his early voyages he met with what he describes as one of the most perilous descents in the whole history of ballooning. The occasion was an evening ascent made from the Vauxhall Gardens one autumn night of 1848. The aeronaut was a Mr. Gypson, and besides Mr. Coxwell there were two other passengers, one of whom was the well-known mountaineer and lecturer, Albert Smith. A number of fireworks which were to be displayed when aloft were slung on a framework forty feet below the car.