Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/212

of Aerostation shows him to possess much higher scientific attainments than balloonists usually have. In fact, Mr Wise stands alone in this respect, as nearly all professional aeronauts are destitute of scientific knowledge.

The number of fatal accidents that have occurred in the history of balloons is not very great, and nearly all have resulted either from the use of the fire-balloon, or from want of knowledge, or carelessness on the part of the aeronauts themselves. We have already referred to the accidents that closed the careers of Pilâtre de Rozier and Zambeccari. On November 25, 1802, Signor Olivari, at Orleans, and on July 17, 1812, Herr Bittorff, at Mannheim, perished in consequence of the accidental combustion of their Montgolfiéres. On April 7, 1806, M. Mosment ascended from Lille upon a platform, from which he accidentally fell and was killed. On July 7, 1819, Madame Blanchard ascended from Paris at night with fireworks attached to the car, a spark from one of which ignited the gas in the balloon, and she was precipitated to the ground and killed. Lieut. Harris ascended from London on May 25, 1824, but, through mismanagement of the valve-line, he allowed all the gas to escape suddenly from the balloon, which descended with terrible velocity. He was killed by the fall, but his companion, Miss Stocks, escaped almost uninjured. In an ascent from Blackburn on September 29, 1824, by Mr Windham Sadler, the balloon, in rising, struck against a chimney, and the aeronaut fell over the side of the car and was killed. On July 24, 1837, Mr Cocking descended from a balloon in a parachute, which struck the ground with such violence that he was killed on the spot. In descending with a horse on September 8, 1850, Lieut. Gale was killed; and in 1863 Mr Chambers was killed at Nottingham, his death arising from suffocation by the gas that poured out at the neck of the balloon, which was not separated from the car by a sufficient interval.

The number of accidents that have occurred bears but a very small proportion to the number of successful ascents that have been made. Mr Monck Mason, in his Aeronautica, gives a list of the names, with the dates and places of their ascent, of all persons who, as far as he could find, had ascended previously to 1838. His list contains 471 names, which are distributed among the inhabitants of the different countries as follows:—England, 313; France, 104; Italy, 18; Germany and the German States, 17; Turkey, 5; Prussia, 3; Russia, 2; Poland, 2; Hungary, 2; Denmark, 1; Switzerland, 1; and the United States, 3. Among these are the names of 49 women, of whom 28 are English, 17 French, 3 German, and 1 Italian. Some of the persons had ascended a great number of times; thus Mr Charles Green's ascents alone amounted to more than 249; and those of the members of the same family to 535. Mr Mason calculated that the whole number of ascents executed by Englishmen was 752. Of the 471 adventurers only nine were killed, and of these six owed their fate to the dangers attendant on the use of the fire-balloon, and one to bravado. The great number of our own countrymen that appear in the above list is no doubt partially due to the fact that it was compiled by an Englishman, to whom English newspapers and other records were more accessible; still there is no reason to doubt that a much greater number of Englishmen have ascended than inhabitants of any other country, as balloons as an amusement at fêtes, &c., have been more common here. The number of Englishmen who have ascended might now be estimated at from 1500 to 2000.

We can call to mind but three fatal casualties that have taken place since Mr Mason compiled his list, viz., Mr Cocking's parachute accident, Mr Gale's death in 1850, and Mr Chambers' death in 1863.

We come now to an account of the use to which the balloon has been applied for the advancement of science. The ascents that have been made are by Sacharof, Biot, and Gay-Lussac in 1804, by Bixio and Barral in 1850, by Mr Welsh in 1852, by Mr Glaisher in 1862–66, and MM. Flammarion and De Fonvielle in 1867–68. We shall give a brief account of these ascents, because, as has been remarked, with a few exceptions, they form the only useful purpose to which the balloon has been applied. The general description of the phenomena, &c., met with in a high ascent, and the general results found, are referred to in the account of Mr Glaisher's experiments, as not only are his accounts more detailed, but the number of ascents made by him is much in excess of that of all the others put together.

The Academy of Sciences at St Petersburg, entertaining the opinion that the experiments made on mountain-sides by De Luc, De Saussure, Humboldt, and others must give results different from those made in free air at the same heights, resolved in 1803 that a balloon ascent should be January made for the purpose of making scientific researches. Accorddingly, on January 30, 1804, M. Sacharof, a member of the academy, ascended, with M. Robertson as aeronaut, in a balloon belonging to the latter, which was inflated with hydrogen gas. The ascent was made at a quarter past seven, and the descent effected at a quarter to eleven. No great height was reached, as the barometer never sank below 23 in., corresponding to less than 1½ mile. The experiments were not very systematically made, and the chief results were the filling and bringing down several flasks of air collected at different elevations, and the supposed observation that the magnetic dip was altered. A telescope was fixed in the bottom of the car pointing vertically downwards, so that the travellers might be able to ascertain exactly the spot over which they were floating at any moment. M. Sacharof found that, on shouting downwards through his speaking-trumpet, the echo from the earth was quite distinct, and at his height was audible after an interval of about ten seconds. M. Sacharof's account is given in the Philosophical Magazine (Tilloch's), vol. xxi. pp. 193–200 (1805).

At the commencement of 1804 Laplace proposed to the members of the French Academy of Sciences that balloons should be employed for the purpose of solving certain physical problems, adding that, as the government had placed funds at their disposal for the prosecution of useful experiments, he thought they might be well applied to this kind of research. The proposition was supported by Chaptal the chemist, who was then minister of the interior, and accordingly the necessary arrangements were speedily effected, the charge of the experiments being given to MM. Gay-Lussac and Biot.

The principal object of this ascent was to determine if the magnetic force experienced any appreciable diminution at heights above the earth's surface, De Saussure having found that such was the case upon the Col du Géant. On August 24, 1804, MM. Gay-Lussac and Biot (the former eminent as a chemist and the latter as a natural philosopher) ascended from the Conservatoire des Arts at ten o'clock in the morning. Their magnetic experiments were incommoded by the rotation of the balloon, but they found that, up to the height of 13,000 feet, the time of vibration of a magnet was appreciably the same as on the earth's surface. They found also that the air became drier as they ascended. The height reached was about 13,000 feet, and the temperature declined from 63° Fahr. to 51°. The descent was effected about half-past one, at Meriville, 18 leagues from Paris.

In a second experiment, which was made on September 16, 1804, M. Gay-Lussac ascended alone. The balloon left the Conservatoire des Arts at 9.40 A.M., and descended at 3.45 P.M. between Rouen and Dieppe. The chief result obtained was that the magnetic force, like gravitation, did