Now I found at seven miles high, and at five and six, that in the absence of all sounds it was not necessary to speak much above a whisper, and that palpitations, watch-ticks, &c., were audible with an increase of sound the higher I got.
Robertson and his friend “could scarcely resist a strong inclination to sleep.”
I not only knew the great importance of keeping wide awake, but felt no desire to do otherwise.
Robertson’s balloon contained only 9,000 cubic feet of hydrogen.
It weighed, with all its apparatus, 5 pood 2 pounds, or a little over 200 pounds, and the weight of the whole was 18 pood 3 pounds.
Now, unless these figures are incorrect, a man like Charles Green might well feel doubtful.
M. Gay-Lussac on September 15th, 1804, when he attained 7016 metres, though well clothed, began to feel cold, he was still “far from experiencing such uneasiness as to oblige him to descend,” his pulse and respiration were accelerated; these were all the inconveniences he felt, and they read to my thinking more correct and natural than Robertson’s.
Green had no belief in what may be styled miraculous ballooning, by that I mean in going up very high or extremely far in a very diminutive balloon.
Practically speaking, irrespective of exact mathematical determinations, a sure and certain test is the amount of ballast taken, together with the volume of gas in the balloon at starting, and the space left for expansion, supposing that the ascent is made with only a partial inflation.
It is useless to boast of distance or height, unless sand equal to the occasion can be taken in the car; and if the diameter and depth of the machine is not in conformity with well established rules, no confidence should be placed in unsupported vapourings, as all the accessories to which I refer must be in order and bear comparison, one with another.