P.M. between Rouen and Dieppe. The chief result obtained was
that the magnetic force, like gravitation, did not experience
any sensible variation at heights from the earth's surface
which we can attain to. Gay-Lussac also brought down air
collected at the height of nearly 23,000 ft., and on analysis
it appeared that its composition was the same as that of air
collected at the earth's surface. At the time of leaving the
earth the thermometer stood at 82 deg. F., and at the highest
point reached (23,000 ft.) it was 14.9 deg. F. Gay-Lussac remarked
that at his highest point there were still clouds above him.
From 1804 to 1850 there is no record of any scientific ascents
in balloons having been undertaken. In the latter year
J. A. Bixio (1808-1865) and A. Barral (1819-1884) made two
ascents of this kind. In the first they ascended from the
Paris observatory on the 29th of June 1850, at 10.27 A.M.,
the balloon being inflated with hydrogen gas. The day was
a rough one, and the ascent took place without any previous
attempt having been made to test the ascensional force of the
balloon. When liberated, it rose with great rapidity, and
becoming fully inflated it pressed upon the network, bulging
out at the top and bottom. The ropes by which the car was
suspended being too short, the balloon soon covered the
travellers like an immense hood. In endeavouring to secure
the valve-rope, they made a rent in the balloon, and the
gas escaped so close to their faces as almost to suffocate
them. Finding that they were descending then too rapidly,
they threw overboard everything available, including their
coats and only excepting the instruments. The ground was
reached at 10h. 45m., near Lagny. Of course no observations
were made. Their second ascent was made on the 27th of
July, and was remarkable on account of the extreme cold met
with. At about 20,000 ft. the temperature was 15 deg. F., the
balloon being enveloped in cloud; but on emerging from the
cloud, at 23,000 ft., the temperature sank to --38 deg. F.,
no less than 53 deg. F. below that experienced by Gay-Lussac
at the same elevation. The existence of these very cold
clouds served to explain certain meteorological phenomena
that were observed on the earth both the day before and the
day after the ascent. Some pigeons were taken up in this,
as in most other high ascents; when liberated, they showed a
reluctance to leave the car, and then fell heavily downwards.
In July 1852 the committee of the Kew Observatory resolved
to institute a series of balloon ascents, with the view of
investigating such meteorological and physical phenomena as
require the presence of an observer at a great height in the
atmosphere. John Welsh (1824-1859) of the Kew Observatory was
the observer, and the great ``Nassau Balloon'' was employed,
with Green himself as the aeronaut. Four ascents were made
in 1852, viz. on the 17th and 26th of August, the 31st of
October and the 10th of November. The heights attained
were 19,510, 19,100, 12,680 and 22,930 ft., and the lowest
temperatures met with in the four ascents were 8.7 deg. F. (19,380
ft.), 12.4 deg. F. (18,370 ft.), 16.4 deg. F. (12,640 ft.) and
10.5 deg. F. (22,370 ft.). The decline of temperature was very
regular. A siphon barometer, dry and wet bulb thermometers,
aspirated and free, and a Regnault hygrometer were taken
up. Some air collected at a considerable height was found
on analysis not to differ appreciably in its composition
from air collected near the ground. For the original
observations see Phil. Trans., 1853, pp. 311-346.
Glaisher's ascents.
At the meeting of the British Association for the Advancement
of Science held at Aberdeen in 1859, a committee was appointed
for the purpose of making observations in the higher strata
of the atmosphere by means of the balloon. For two years
nothing was effected, owing to the want both of an observer
and of a suitable balloon. After its reappointment at
the Manchester meeting of 1861, the committee communicated
with Henry Tracey Coxwell (1819-1900), an aeronaut who had
made a good many ascents, and he agreed to construct a new
balloon, of 90,000 cub. ft. capacity, on the condition that
the committee would undertake to use it, and pay L. 25 for
each high ascent made especially on its behalf, defraying
also the cost of gas, &c., so that the expense of each high
ascent amounted to nearly L. 50. An observer being still
wanted, James Glaisher, a member of the committee, offered
himself to take the observations, and accordingly the first
ascent was made on the 17th of July 1862, from the gas-works
at Wolverhamiton, this town being chosen on account of its
central position in the country. Altogether, Glaisher made
twenty-eight ascents, the last being on the 26th of May
1866. Of these only seven were specially high ascents,
although six others were undertaken for the objects of the
committee alone. . On the ether occasions he availed himself
of public ascents from the Crystal Palace and other places
of entertainment, merely taking his place like the other
passengers. In the last six ascents another aeronaut and a
smaller balloon were employed. The dates, places of ascent
and greatest heights (in feet) attained in the twenty-eight
ascents were--1862: July 17, Wolverhampton, 26,177; July 30,
Crystal Palace, 6937; August 18, Wolverhampton, 23,377; August
20, Crystal Palace, 5900; August 21, Hendon, 14,355; September
1, Crystal Palace, 4190; September 5, Wolverhampton, 37,000;
September 8, Crystal Palace, 5428. 1863: March 31, Crystal
Palace, 22,884; April 18, Crystal Palace, 24,163; June 26,
Wolverton, 23,200; July 11, Crystal Palace, 6623; July 21,
Crystal Palace, 3298; August 31, Newcastle-upon-Tyne, 8033;
September 29, Wolverhampton, 16,590; October 9, Crystal Palace,
7310. 1864: January 12, Woolwich, 11,897; April 6, Woolwich,
11,075; June 13, Crystal Palace, 3543; June 20, Derby, 4280;
June 27, Crystal Palace, 4898; August 29, Crystal Palace,
14,581; December 1, Woolwich, 5431; December 30, Woolwich,
3735. 1865: February 27, Woolwich, 4865; October 2, Woolwich,
1949; December 2, Woolwich, 4628. 1866: May 26, Windsor, 6325.
The primary object of the ascents was to determine the temperature
of the air, and its hygrometrical state at different elevations
to as great a height as could be reached; and the secondary
objects were-(1) to determine the temperature of the dew-point
by Daniell's and Regnault's hygrometers, as well as by the
dry and wet bulb thermometers, and to compare the results;
(2) to compare the readings of an aneroid barometer with those
of a mercurial barometer up to the height of 5 m.; (3) to
determine the electrical state of the air, (4) the oxygenic
condition of the atmosphere, and (5) the time of vibration
of a magnet; (6) to collect air at different elevations;
(7) to note the height and kind of clouds, their density and
thickness; (8) to determine the rate and direction of different
currents in the atmosphere; and (9) to make observations on
sound. The instruments used were mercurial and aneroid
barometers, dry and wet bulb thermometers, Daniell's dew-point
hygrometer, Regnault's condensing hygrometer, maximum and
minimum thermometers, a magnet for horizontal vibration,
hermetically sealed glass tubes exhausted of air, and an
electrometer. In one or two of the ascents a camera was taken up.
The complete observations, both as made and after reduction,
are printed in the British Association Reports, 1862-1866;
here only a general account of the results can he given.
It appeared that the rate of the decline of temperature with
elevation near the earth was very different according as
the sky was clear or cloudy; and the equality of temperature
at sunset and increase with height after sunset were very
remarkable facts which were not anticipated. Even at the
height of 5 m., cirrus clouds were seen high in the air,
apparently as far above as they seem when viewed from the
earth. The results of the observations differed very much,
and no doubt the atmospheric conditions depended not only
on the time of day, but also on the season of the year, and
were such that a vast number of ascents would be requisite
to determine the true laws with anything approaching to
certainty and completeness. It was also clear that England is
a most unfit country for the pursuit of such investigations,
as, from whatever place the balloon started, it was never
safe to be more than an hour above the clouds for fear of
reaching the sea. It appeared from the observations that an
aneroid barometer could be trusted to read as accurately as
a mercurial barometer to the heights reached. The time of
vibration of a horizontal magnet was taken in very many of the
ascents, and the results of ten different sets of observations
indicated that the time of vibration was longer than on the
earth. In almost all the ascents the balloon was under the
influence of currents of air in different directions which
varied greatly in thickness. The direction of the wind on the
earth was sometimes that of the whole mass of air up to 20,000
ft., whilst at other times the direction changed within 500
ft. of the earth. Sometimes directly opposite currents were
met with at different heights in the same . ascent, and three
or four streams of air were encountered moving in different
directions. The direct distances between the places of ascent
and descent, apart from the movements of the balloon under
the influence of these various currents, were always very much
greater than the horizontal movement of the air as measured by
anemometers. For example, on the 12th of January 1862, the
balloon left Woolwich at 2h. 8m. P.M., and descended at
Lakenheath, 70 m. distant from the place of ascent, at 4h.
19m. P.M. At the Greenwich Observatory, by a Robinson
anemometer, during this time the motion of the air was 6 m.
only. With regard to physiological observations, Glaisher
found that the frequency of his pulse increased with elevation,
as also did the number of inspirations. The number of his
pulsations was generally 76 per minute before starting,
about 90 at 10,000 ft., 100 at 20,000 ft., and 110 at higher
elevations. But a good deal depended on the temperament of the
individual. This was also the case in respect to colour; at
10,000 ft. the faces of some would be a glowing purple, whilst
others would be scarcely affected; at 4 m. high Glaisher
found the pulsations of his heart distinctly audible, and
his breathing was very much affected, so that panting was
produced by the slightest exertion; at 29,000 ft. he became
insensible. In reference to the propagation of sound, it
was at all times found that sounds from the earth were more
or less audible according to the amount of moisture in the
air. When in clouds at 4 m. high, a railway train was heard;
but when clouds were far below, no sound ever reached the ear
at this elevation. The discharge of a gun was heard at 10,000
ft. The barking of a dog was heard at the height of 2 m.,
while the shouting of a multitude of people was not audible
at heights exceeding 4000 ft. In his ascent of the 5th of
September 1862, Glaisher considered that he reached a height
of 37,000 ft. But that figure was based, not on actual
record, but on the circumstances that at 29,000 ft., when he
became insensible, the balloon was rising 1000 ft. a minute,
and that when he recovered consciousness thirteen minutes
later it was falling 2000 ft. a minute, and the accuracy of
his conclusions has been questioned. Few scientific men have
