298 SCIENTIFIC RECREATIONS. 



the Godard " Montgolfier " balloon, which was one hundred and seventeen 

 feet high, and carried a stove. We give illustrations of these celebrated 

 balloons, and will now pass on to the more scientific portion of the subject 

 and the ascents of Mr. Glaisher and other aeronauts for the purpose of 

 making meteorological observations, and the use of balloons for purposes of 

 observation in war. 



It appears that the first ascent for scientific investigation was made in 

 the year 1803. The aeronauts were Messrs. Robertson and Lhoest. They 

 ascended from Hamburg and came down at Hanover, and made meantime 

 several experiments with reference to the electrical condition of the atmo- 

 sphere, its influence upon a magnetic needle, and some experiments with 

 regard to acoustics and heat. The report was presented to the St. Petersburg 

 Academy, and contains the result of their interesting observations. The 

 travellers ascertained that at the elevation to which they attained, viz., 

 25,500 feet, the temperature was on that July day fifty degrees colder, 

 falling to 19*6, while on the earth the thermometer had shown 68. They 

 ascertained that glass and wax did not become electric when rubbed, that 

 the Voltaic battery lost much of its power, that the oscillation of a " dipping 

 needle" increased as they mounted into the air, while sound was certainly 

 less easily transmitted at that elevation, and struck them as less powerful in 

 tone. The heat experiment was not a success, owing to the breaking of the 

 thermometer. They wished to find the temperature of boiling water at that 

 elevation, but when the experiment was about to be made Robertson acci- 

 dentally plunged the instrument into the fire instead of into the water. So 

 the question was not settled. 



The effect upon the aeronauts was a sensation of sleepiness, and two 

 birds died. The muscular powers of the voyagers also appear to have been 

 much affected, and similar sensations may be experienced by travellers on 

 high mountains who find their breath very short and a disinclination to 

 exertion oppress them. 



MM. Biot and Gay-Lussac made a very interesting ascent in 1804. 

 We will detail their experiences at some length, for the coolness displayed 

 and the value of the observations made are remarkable in the history of 

 scientific ballooning. They started at 10 o'clock a.m. on the 23rd of 

 August, and when the balloon had carried them up to an altitude of 8,600- 

 feet they commenced their experiments. They had some animals in the 

 car with them, a bee amongst the number, and the insect was let go first 

 It flew away swiftly, not at all inconvenienced apparently. The sun wa^ 

 very hot at 56 Fahr. Their pulses were beating very fast, but no incon- 

 venience was felt. 



When 11,000 feet had been reached a linnet was permitted to go at 

 large, but after a little time the bird returned to the balloon. It remained 

 perched for a few minutes, and then dashed downwards at a tremendous 

 pace. A pigeon was then liberated. It also appeared very uncertain, and 

 wheeled around in circles for a time. At last it gained confidence and 



