Chapter I. Experiments of Robertson, Lhoest, Saccarof, &c.
Robertson is regarded by many as a sort of mountebank; yet such men as Arago have put themselves to the trouble of examining the aerostatic feats of this aeronaut, and of examining the results of his observations.
“The savant Robertson,” says Arago, “performed at Hamburg on the 18th of July, 1803, with his countryman, Lhoest, the first aeronautic voyage from which science has been able to draw useful deductions. The two aeronauts remained suspended in the air during five hours, and came down near Hanover, twenty-five leagues from the spot from which they set off.”
The first time that Robertson appears in the annals of aerostation is in 1802, on the occasion of the sale of the balloon used at the battle of Fleurus, of which mention will be made in the chapter on military aerostation. But three years previously he had been instructed to make a balloon of an original form, which should ascend in honour of the Turkish ambassador at the garden of Tivoli. The fete was completely successful. Turks, Chinese, Persians, and Bedouins will always be welcome, as on this occasion, at Paris, appearing as they do only at rare intervals, and for a short time.
The fete took place on the 2nd of July. Robertson presented himself at the house of Esseid-Ali, to obtain his autograph. The Turkish ambassador willingly granted the request, and wrote his name in letters, each of which was two inches in height, on a sheet of paper. He then offered the aeronaut coffee and comfits, and promised to be present to witness the balloon ascent. His name was painted in large characters on a balloon fifteen feet in diameter, and on the form of which was the figure of a crescent. The experiment delighted the ambassador, and was well received by the public.
Jacques Garnerin, when he came to make his debut as an aeronaut, made an attempt with the parachute, the following August, at the garden of the Hotel de Biron. The ambassador was asked to honour the fete, but he declined, saying that he had “made up his mind that man was not intended for flying—Mahomet had not so willed it.”
Of one of Robertson’s more interesting ascents he himself has left us the following sketch:—
“I rose in the balloon at nine a.m., accompanied by my fellow-student and countryman, M. Lhoest. We had 140 lbs. of ballast. The barometer marked twenty-eight inches; the thermometer sixteen degrees Reaumur. In spite of some slight wind from the north-west, the balloon mounted so perpendicularly that in all the streets each of the spectators believed we were mounting straight up above his head. In order to quicken our ascent I discharged a parachute made of silk, and weighted in a way to prevent oscillations. The parachute descended at the rate of two feet per second, and its descent was uniform. From the moment when the barometer began to sink we became very careful of our ballast, as we wished to test from experience the different temperatures through which we were about to pass.
“At 10.15, the barometer was at nineteen inches, and the thermometer at three above zero. We now felt all the inconvenience of an extremely rarefied atmosphere coming upon us, and we commenced to arrange some experiments in atmospheric electricity. Our first attempts did not succeed. We threw over part of our ballast, and mounted up till the cold and the rarefaction of the air became very troublesome. During our experiments we experienced an illness throughout our whole system. Buzzing in the cars commenced, and went on increasing. The pain we felt was like that which one feels when he plunges his head in water. Our chests seemed to be dilated, and failed in elasticity. My pulse was quickened, M. Lhoest’s became slower; he had, like me, swelled lips and bleeding eyes; the veins seemed to come out more strongly on the hands. The blood ran to the head, and occasioned a feeling as if our hats were too tight. The thermometer continued to descend, and, as we ascended, our illness increased, and we could with difficulty keep awake. Fearing that my travelling companion might go to sleep, I attached a cord to my thigh and to his, and we held the extremities of the cord in our hands. Thus trammelled, we had to commence the experiments which I had proposed to make.