Part 11 (1/2)
Chapter I Experiments of Robertson, Lhoest, Saccarof, &c
Robertson is regarded by o have put the the aerostatic feats of this aeronaut, and of exa the results of his observations
”The savant Robertson,” says Arago, ”perfor on the 18th of July, 1803, with his countrye from which science has been able to draw useful deductions The two aeronauts re five hours, and caues 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 inal form, which should ascend in honour of the Turkish aarden of Tivoli The fete was completely successful Turks, Chinese, Persians, and Bedouins will always be welco as they do only at rare intervals, and for a short time
The fete took place on the 2nd of July Robertson presented hiraph The Turkish aranted the request, and wrote his naht, on a sheet of paper He then offered the aeronaut coffee and comfits, and promised to be present to witness the balloon ascent His nae characters on a balloon fifteen feet in diaure of a crescent The experihted the ambassador, and ell received by the public
Jacques Garnerin, when he came to make his debut as an aeronaut, ust, at the garden of the Hotel de Biron The ambassador was asked to honour the fete, but he declined, saying that he had ”--Mahomet had not so willed it”
Of one of Robertson'ssketch:--
”I rose in the balloon at nine am, accompanied by my fellow-student and countryman, M Lhoest We had 140 lbs of ballast The barorees Reauht wind from the north-west, the balloon mounted so perpendicularly that in all the streets each of the spectators believed ere ht up above his head In order to quicken our ascent I discharged a parachute hted in a way to prevent oscillations The parachute descended at the rate of two feet per second, and its descent was uniforan to sink we became very careful of our ballast, as ished to test froh which ere about to pass
”At 1015, the barometer was at nineteen inches, and the thermometer at three above zero We now felt all the inconvenience of an extre upon us, and we coe 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 beca our experihout our whole syste 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 beca eyes; the veins seely 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 o to sleep, I attached a cord to h 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 lass, the brimstone, and the Spanish ere not electrified in a ns under friction--at least, I obtained no electricity from the conductors or the electro of sixty couples--silver and zinc It worked very well on the occasion of our departure froree to the electroave only five-sixths of a degree to the saalvanic flame seemed more active at this elevation than on the earth
”I took two birds withinto the balloon--one of these was now dead, the other appeared stupefied After having placed it upon the brink of the gondola, I tried to frighten it to s, but did not leave the spot; then I left it to itself, and it fell perpendicularly and with great rapidity Birds are certainly not able to maintain themselves at such elevations
”It is notable that the atrey and misty above our heads, and the beautiful blue sky seen froh the weather was calm and serene, and the day theto us, and its heat was di to our elevation
”At half-past eleven, the balloon was no longer visible fro
The heavens were so pure beneath us that everything was distinctly seen by us, though veryseemed only a red point in our eyes; the Elbe looked like a straight ribbon I wished to lass, but what surprised me was that when I lifted it up it was so cold that I had to wrap my handkerchief around it to enableable to support our position any longer, we descended, after having used up ree of terror a the inhabitants which the size of our balloon was calculated to inspire in a country where such machines had never before been seen We descended above a poor village called Radenburg, a place areat alarm, and even the beasts of the field fled from us
”While our balloon rapidly approached the earth, aved our hats and flags, and shouted to the inhabitants, but our voices only increased their terror The villagers rushed aith cries of terror, leaving their herds, whose bellowings increased the general alarround, everyappealed in vain, and fearing that the villagers ht do us so this second ascent, we threw over all our ballast; but in this ere iht, and having lost as, I perceived that our descent would be very rapid, and to provide against accident, I gathered together all the instruments, the bread, the ropes, and even such money as we had with us, and placed them in three sacks, to which I attached a rope of a hundred feet in length This precaution saved us a shock The weight, around before us, and the balloon, thus lightened, caround between Wichtenbech and Hanover, after having run twenty-five leagues in five and a half hours”
After this ascent Robertson becast others with Professor Pfaff, as interested in aerial travelling as a ical problems Some days after Robertson's ascent, the professor wrote to hien gas will find itself in equilibriuht is the extreas has an elasticityas it ions of the atht of atmospheric air diminishes; and it will not cease to mount until it rises above the atmosphere itself, if two conditions be coasthe balloon as it rises; 2, the condition that the gas shall not be allowed to mix at all with the ated for the 14th of August, in which Robertson was to be acco to the entreaties of his fao ”I went up with my friend Lhoest,”
says Robertson, ”at forty-two minutes past twelve midday In a minute or te rose up between two masses of cloud, which seee The upper surfaces of these clouds are not uniformly level, like the under sides seen from the earth, but they are of a conical or pyra masses seeulf it, but this optical illusion was due to the apparent i at the rate of about twenty feet per second
”The fear of losing the view of the Baltic, which we perceived between the clouds at intervals, obliged us to renounce the project of rising as high as on the last occasion The baroree below zero, when I let off two pigeons