erschel was compelled to
relinquish his theory of equal star distribution, and found, as he
approached the Galaxy, that the stars became much more numerous, and
that in the Milky Way itself there was evidence of the gravitation of
stars towards certain regions forming aggregations and clusters which
would ultimately lead to its breaking up into numerous separate sidereal
systems. As he extended his survey of the heavens and examined with
greater minuteness the stellar regions in the Galactic tract, he
discovered that by his method of star-gauging he was unable to define
the complexity of structure and variety of arrangement which came under
his observation; he also perceived that the star-depths are
unfathomable, and discerned that beyond the reach of his telescope there
existed systems and galaxies of stars situated at an appalling distance
in the abysmal depths of space. Though the magnitude of that portion of
the sidereal heavens which came under his observation was inconceivable
as regards its dimensions, Herschel was able to perceive that it formed
but a part--and most probably a small part--of the stellar universe, and
that without a more extended knowledge of this universe, which at
present is unattainable, it would be impossible to determine its
structural configuration or discover the relationships that exist among
the sidereal systems and Galactic concourses of stars distributed
throughout space. Herschel ultimately abandoned his star-gauging method
of observation and confined his attention to exploring the star depths
and investigating the laws and theories associated with the bodies
occupying those distant regions.

Since all the planets if viewed from the Sun would be seen to move
harmoniously and in regular order round that body, so there may be
somewhere in the universe a central point, or, as some persons imagine,
a great central sun, round which all the systems of stars perform their
majestic revolutions with the same beautiful regularity; having their
motions controlled by the same law of gravitation, and possessing the
same dynamical stability which characterises the mechanism of the solar
system.

The extent of the distance which intervenes between our system and the
fixed stars constituted a problem which exercised the minds of
astronomers from an early period until the middle of the present
century.

Tycho Brahe, who repudiated the Copernican theory, asserted as one of
his reasons against it th