no
illness from the rarefied air. M. Bixio did not feel the sharp pains in
the ears from which he had suffered on the former occasion. They passed
through a mass of cloud 15,000 feet in thickness, and they had not yet
passed quite through it, when at the height of over 21,000 feet from the
ground, they began to descend, their descent being caused by a rent in
the envelope of the balloon, from which the gas escaped. They might, in
throwing out the last of their ballast, have, perhaps, prolonged for a
little their sojourn in space, but the circumstances in which they were
placed did not permit them to make many more scientific observations
than those they had made, and thus they were obliged to submit to their
fate. When they had reached their greatest height, there seemed to open
up in the midst of the vaporous mass a brilliant space, from which they
could see the blue of heaven. The polariscope, directed towards this
region, showed an internal polarisation, but, when pointed to the side
where the mist still prevailed, there was no polarisation.

An optical phenomenon of a remarkable kind was witnessed when the
voyagers had attained their highest point. They saw the sun through the
upper mists, looking quite white, as if shorn of its strength; and, at
the same time, below the horizontal plane, below their horizon, and at
an angular distance from the plane equal to that of the sun above it,
they saw a second sun, which resembled the reflection of the actual sun
in a sheet of water. It is natural to suppose that the second sun was
formed by the reflection of the sun's rays upon the horizontal faces of
the ice crystals floating in this high cloud.

Chapter III. Ascents of the Mssrs. Welsh, Glaisher and Coxwell.

The most recent balloon ascents in England deserving attention have been
undertaken for scientific objects, and in this country, more than in
any other, it may be said that the conquest of the air has been made to
serve a practical end.

In July, 1852, the Committee of the Kew Observatory resolved to
undertake a number of balloon voyages. This resolution was approved
of by the British Association for the Advancement of Science, and the
necessary instruments for making a number of meteorological observations
were prepared. The balloon employed was that of Mr. Green, who was
accompanied in his ascents by Mr. Welsh. The greatest height to which
Mr. Welsh rose was on the fourth ascent which took place on the 10th