ON EIGHT BALLOON ASCENTS IN 1862. 493 
GENERAL REMARKS. 
These eight ascents have led me to conclude, firstly, that it was necessary 
to employ a balloon containing nearly 90,000 cubic feet of gas; and that it 
was impossible to get so high as six miles, even with a balloon of this mag- 
nitude, unless carburetted hydrogen, varying in specific gravity from 370 to 
330, had been supplied for the purpose. 
It is true that these statements are rather conflicting when compared with 
the statements made by one or two early travellers, who professed to have 
reached some miles in height with small balloons. But if we recollect that 
at 32 miles high a volume of gas will double its bulk, we have at once a 
ready means of determining how high a balloon can go; and in order to reach 
an elevation of six or seven miles it is obyious that one-third of the capacity 
of the balloon should be able to support the entire weight of the balloon, in- 
clusive of sufficient ballast for the descent. 
The amount of ballast taken up affords another clue as to the power of 
reaching great heights. Gay-Lussac’s ballast, as before mentioned, was re- 
duced to 33 lbs. Rush and Green, when their barometers, as stated by them, 
stood at 11 inches, had only 70 lbs. left, and this was considered a sufficient 
playing-power. We found that it was desirable to reserve five or six hun- 
dred pounds; and although we could have gone higher by saving less, still 
on every occasion it was evident that a large amount of ballast was indis- 
pensable to regulate the descent and select a favourable spot for landing. 
Secondly, it was manifest throughout our various journeys that excessive 
altitude and extended range as to distance are quite incompatible. The 
reading of the instruments establishes this ; and it has been pointed out what 
a short time the balloon held its highest place, and how reluctantly it ap- 
peared to linger even at a somewhat less elevation. This was not owing to 
any leakage or imperfection in the balloon itself, for its efficiency has been 
well tested, and it remained intact a whole night without the least percep- 
tible loss of gas. 
It has been stated by an aéronaut of experience that strong opposing upper 
currents have been heard to produce an audible contention, and to sound like 
the “roaring of a hurricane.” Now, the only deviation we experienced from 
the most perfect stillness was a slight whirring noise in the netting, and this 
only when the balloon was rising with great rapidity, and a slight flapping 
on descending, when the balloon is in a collapsed state. 
I may also state that the too readily accepted theory as to the prevalence 
of a settled west or north-west wind was not confirmed in our trips. Nor 
was the appearance of the upper surface of the clouds such as to establish 
the theory that the clouds assume a counterpart of the earth’s surface below, 
and rise or fall like hills or dales. 
The formation of vapour along the course and sinuosities of the river 
during an ascent from the Crystal Palace has been already alluded to; this 
was a very remarkable demonstration. 
GENERAL ConcLusions. 
Perhaps the most important conclusions which can be drawn from the 
experiments at present are :— 
1, That the temperature of the air does not decrease uniformly with 
increase of elevation above the earth’s surface, and consequently 
the theory of a decline of temperature of 1° in every 300 feet must 
