The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1893-11-17
TEN MILES ABOVE THE EARTH.
Interesting Experiments at the Higg est
Point Balloon Ever Reached.

One of the most interesting expert
ments with balloons that has ever been
undertaken was that of Messrs. Hermite
and Besanconat Paris-V aughsard. They
succeeded in sending balloon to the
unprecedented elevation of ZIG, 900
meters, or about ten miles. There We're
no people in the balloon, but it carried
variety of STRENGTHENING instruments,
designed to record the tempe nature, the
atmospheric prssure, etc. The little bal
loon was strarted on it's lofty trip about
noon, when the air was remarkably still
and clear. 1t rose rapidly, ssand in three
quarters of an hour had attained an
elevation of ten miles, at which height
it remained for several hours
1t was there subjected to an atmos-
pheric pressure only about one-eighth as
great as that st the surface of the earth,
and NJ. Hermite explains this floating for
so long time at a constant height by
supposing that the temperature does not
vary sensibly with the elevation of the
floating body after the latter has at
tanned an altitude where seven--eighths
of the atmospheric pressure is lacking
and where there remains no trace of
water vapor.
But toward six o'clock, when, with
the decline of the way, the temperature
began rapidly to fall, the balloon start
ed back toward the earth, arriving, with
a gentle motion which did not disturb
the instruments carried, at I'll at
Ghanyres, near Paris-V Vanguard, from
which it had started.
The balloon was visible with q tele-
scope during the entire time. 1t shone
like the planet Venus seen by day. By
means of micrometer' attached to an
astronomical telescope the apparent
t.iameter of the balloon could easily
have been measured, and this would have
furnished means of calculating its al
titude independent of the record of the
barometer which it carried.
The barometer and thermometer were
furnished with automatic pens driven
by c1ockwork, by means of which dia-
grams of the changes of pressure and
temperature that the balloon experienced
were obtained. At the height of about
I 3-4 miles the thermometer marked
Temperature of 60 deg. Fair. below zero.
Then the ink in the registering pens of
both the thermometer and the barome-
ter became frozen and the records were
interrupted.
But, as the balloon continued to rise,
the ink thawed again, and at the ten
mile level the automatic records were
renewed. The temperature registered
fhern was only about g degrees below
zero. The increase of temperature is
ascribed to the effect of the unclouded
sun heating the air in the ba ket that
tanned the instruments The lowest
record of the barometer was t103
millimeters, or trifle more than four
inches.
M.Hermite calls attention to the fact
that the density of the air at the heigh t
often miles, where the balloon remained
during most of the afternoon, is less
than that existing upon the plains Of the
moon on the assumption that the atnos-
pheric density of the moon is proper
toned to the force of gravity at the sur
face of that orb.
If this is correct, then the instruments
would have behaved about the same if
M. Hermite had been able to place them
on the moon as they did when he sent
them only 20 miles above the earth
Youths Companion.