rmer. So, also, when the sky is entirely
overcast and rain is altogether or generally absent, the aeronaut, upon
traversing the canopy immediately above him, is sure to enter upon an
upper hemisphere either perfectly cloudless or nearly so. These remarks
were, we believe, first made by Mr. M. Mason, and he states that they
have been verified during many hundred ascents.

In October, 1837, two ascents were made by Mr. Mason, which well
illustrate what has been said. On the 12th, "the sky was completely
overspread with clouds, and torrents of rain fell incessantly during the
whole of the day. Upon quitting the earth, the balloon was almost
immediately enveloped in the clouds, through which it continued to work
its way upwards for a few seconds. Upon emerging at the other side of
this dense canopy, a vacant space, of some thousand feet in breadth,
intervened, above which lay another stratum of a similar form and
observing a similar character. As the rain, however, still continued to
pour from this second layer of clouds, to preserve the correctness of the
observation, a third layer should, by right, have existed at a still
further elevation; which, accordingly, proved to be the case. On the
subsequent occasion of the ascent of the same balloon, (October 17th,) an
exactly similar condition of the atmosphere, with respect to clouds,
prevailed; unaccompanied, however, with the slightest appearance of rain.
No sooner had the balloon passed the layer of clouds immediately above
the surface of the earth, than, as was anticipated, not a single cloud
was to be found in the firmament beyond; an unbroken expanse of clear
blue sky everywhere embracing the frothy plain that completely
intercepted all view of the world beneath."

Mr. Howard had not the advantages of a balloon to assist his
observations. He has noticed that during rain and before the arrival of
the denser and lower clouds, or through their interstices, there exists,
at a greater height, a thin light veil or a hazy appearance. When this
has considerably increased, the lower clouds are seen to spread till they
unite in all points and form one uniform sheet. The rain then commences,
and the lower clouds arriving from the windward, move under this sheet
and are successively lost in it. When the latter cease to arrive, or
when the sheet breaks, letting through the sun-beams, every one's
experience teaches him to expect that the rain will abate or leave off.

But