BALLOON ASCENTS. 405 
one elevation and reaching another was so great that the two 
could not be otherwise than very loosely related. 
A¥hen_, therefore^ the first balloon ascent was made with 
human beings^ who recorded the history of their sensations 
and the conditions of the atmosphere at various elevations, as 
the natural incidents and circumstances of their voyage, a 
practical application of the balloon to the purposes of those 
aerial researches of De Saussure was thus spontaneously 
suggested. 
Seventeen years, however, passed before Gay-Lussac soli- 
cited the French Government for the use of the balloon in 
which he ascended to the height of 23,000 feet. Yery great 
were the expectations, and much disappointment followed 
this memorable journey. 
Account had not been taken of the want of sensitiveness of 
the instruments, and that the balloon would be constantly 
moving, so that readings taken at one elevation really belonged 
to another, either much below or much above, according as 
the balloon was ascending or descending, through that space 
of time required for the instruments to take up true readings. 
When far more sensitive and accurate instruments were con- 
structed, by modern opticians, a desire again arose to ascend 
into the atmosphere, and the British Association appointed a 
committee, consisting of Col. Sykes, M.P., the Astronomer 
Eoyal, Lord Wrottesley, Sir David Brewster, Sir J. Herschel, 
Bart., Dr. Lloyd, Admiral Fitz-Roy, Dr. Lee, Dr. Robinson, 
Mr. Gassiot, Dr. Fairbairn, Dr. Miller, Dr. Tyndal, and myself, 
for carrying out these experiments ; and it is under this com- 
mittee the experiments have been made. 
Elevations by means of the balloon are gained so easily, 
and without fatigue, that an observer, thus situated at different 
heights, separated from all connection with the earth, and 
quite free from any unpleasant sensation till he passes beyond 
three miles, is by far better situated than the Alpine traveller. 
He can^ prove the history of physiological sensations, and 
best pursue physical researches generally. In this case he 
travels free from the effects of muscular exertion, which makes 
fatigue so formidable in the higher regions of the earth^s sur- 
face; and, apart from all terrestrial influence, can investigate 
the true conditions of the atmosphere, with instruments com- 
plete, carefully arranged, and always ready for use ; advantages 
which speak for themselves. He can also repeat to-morrow 
that which he has done to-day, and successively in the different 
seasons of the year. 
It will be convenient here to speak of the subjects of 
research by means of balloons with which I was charged. 
The first in importance was the confirming or otherwise the 
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