Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1854-09-21
AN OPTICAL ILLUSION.

As we promised our readers yesterday, we will
now attempt to give an idea of the optical ilu-
sion seen by Prof George Elliott last Wednes-
day, In his ascension from this city. In order
to do SO, however, 50 as to be undarstood, we
presume we shall be freely excused in commen-
cling with short preface.
After he had ascended about three THOUSAND
feet he discharged some FIVE pounds of his ballast
when he shot onward and upward with ANA
zing rapidity, till he began to approximate to
the clouds. He then discharged about five more
pounds of sand, the remainder of the bag, when
he again darted upward among the clouds, which
were so dense as to wholly exclude all terrestrial
objects from his view, and of course he was lost
to all observers below. The discharges of ballast
were distinctly seer. from below, and on the first
occasion some one exclaimed that the balloon had
bursted
While among the clouds, he says it seemed to
him as if he was in the midst of a large ground
glass globe, some two or three hundred feet in
diameter, against the side of which, opposite to
the sun, the shadow Of the Lady Isabella, (his
balloon,) rested, some five or six times larger
than the corporeal one. About half way between
him and the shadow, which seemed as if resting
on the glass wall, another balloon was seen of
size between the shadow and the real one,
resting as if in a vacuum. which displayed every
color faithfully of the original. He then saw
another Elliott, clad and with features like him
self, and seemingly selG-like. He extended his
fingers, when he was mimicked by this image;
and whether he extended one finger. or more, or
whatever he did, this figure duplicated exactly
When he would cause his balloon to oscilate,
this balloon would move exactly like his. When
he threw out mora ballast to elevate himself,
this figure sank doicn instead of rising with him,
rays of the unclouded sun, he left the mimic
ereonaut below him.
In the rays of the sun above the clouds he
found it so warm as to cause him to perspire
freely state of heat never before experienced at
this height, nearly twenty-four thousand feet,
where the air is very rariicd and generally very
chilly. lie then opened the valve for the pur-
pose of descending, and as soon as he sunk one
or two thousand feet, which he ascertained by
barometrical observations, he felt as if he had
entered an ice house, and cold chill seized his
whole person
Here he again met his mimic Mral voyager,
whom he kept in company for some time, from
philosophical motives. Whenever he moved
sideways, this mum gentleman would move in
the same direction. But when he moved up or
down, the duplicate would move in directly
opposite way and when he concluded to de-
scend, the image moved upward until the tri-
colored flask was out of sight, when he could
sec the Car and the aeronaut still standing in it
as i'll basket attached to nothing He still
kept looking until his head was Robaspierred,
and finally, piece by piece, his body, and at last
his feet and basket ascended entirely out of his
sight.
Professor Elliott says that he has been up u
hundred and one times, but never saw anything
in the form of an illusion like this before and
he asks the opinions of the scientific and learned
as to the probable cause Of this remarkable phe-
nomcnon, for the information of the public
! PetersJurgh (Vd y Intelhgeacer