at the distances by which the heavenly bodies
are separated from each other were greater than even the upholders of
this theory believed them to be. Although the distance of the Sun from
the Earth was unknown, Tycho was aware that the diameter of the Earth's
orbit must be measured by millions of miles, and yet there was no
perceptible motion or change of position of the stars when viewed from
any point of the vast circumference which she traverses. Consequently,
the Earth, if viewed from the neighbourhood of a star, would also appear
motionless, and the dimensions of her orbit would be reduced to that of
a point. This seemed incredible to Tycho, and he therefore concluded
that the Copernican theory was incorrect.

The conclusion that the stars are orbs resembling our Sun in magnitude
and brilliancy was one which, Tycho urged, should not be hastily
adopted; and yet, if it were conceded that the Earth is a body which
revolves round the Sun, it would be necessary to admit that the stars
are suns also. If the Earth's orbit, as seen from a star, were reduced
to a point, then the Sun, which occupies its centre, would be reduced to
a point of light also, and, when observed from a star of equal
brilliancy and magnitude, would have the same resemblance that the star
has when viewed from the Earth, which may be regarded as being in
proximity to the Sun. Tycho Brahe would not admit the accuracy of these
conclusions, which were too bewildering and overwhelming for his mental
conception.

But the investigations of later astronomers disclosed the fact that the
heavenly bodies are situated at distances more remote from each other
than had been previously imagined, and that the reasons which led Tycho
to reject the Copernican theory were based upon erroneous conclusions,
and could, with greater aptitude, be employed in its support. It was
ascertained that the distance of the Sun from the Earth, which at
different periods was surmised to be ten, twenty, and forty millions of
miles, was much greater than had been previously estimated. Later
calculations determined it to be not less than eighty millions of miles,
and, according to the most recent observations, the distance of the Sun
from the Earth is believed to be about ninety-three millions of miles.

Having once ascertained the distance between the Earth and the Sun,
astronomers were enabled to determine with greater facility the
distances of other heavenly bodies.

It was now kno