of day and night, by
carrying all the other spheres round the Earth once in every twenty-four
hours. The Primum Mobile enclosed, as if in a shell, all the other
spheres, in which was included the created universe, and, although of
vast dimensions, its conception did not overwhelm the mind in the same
manner that the effort to comprehend infinitude does.

Beyond this last sphere there was believed to exist a boundless,
uncircumscribed region, of immeasurable extent, called the Empyrean, or
Heaven of Heavens, the incorruptible abode of the Deity, the place of
eternal mysteries, which the comprehension of man was unable to fathom,
and of which it was impossible for his mind to form any conception. Such
were the imaginative beliefs upon which this ancient astronomical theory
was founded, that for a period of upwards of two thousand years held
undisputed sway over the minds of men, and exercised during that time a
predominating influence upon the imagination, thoughts, and conceptions
of all those who devoted themselves to literature, science, and art. Of
the truthfulness of this assertion there is ample evidence in the
poetical, philosophical, and historical writings of ancient authors,
whose ideas and conceptions regarding the created universe were limited
and circumscribed by this form of astronomical belief. In the works of
more recent writers we find that it continued to assert its influence;
and among our English poets, from Chaucer down to Shakespeare, there are
numerous references to the natural phenomena associated with this
system, and most frequently expressed by poetical allusions to 'the
music of the spheres.'

The ideas associated with the Ptolemaic theory were gratifying to the
pride and vanity of man, who could regard with complacency the paramount
importance of the globe which he inhabited, and of which he was the
absolute ruler, fixed in the centre of the universe, and surrounded by
ten revolving spheres, that carried along with them in their circuit all
other celestial bodies--Sun, Moon, and stars, which would appear to have
been created for his delectation, and for the purpose of ministering to
his requirements. But when the Copernican theory became better
understood, and especially after the discovery of the law of universal
gravitation, this venerable system of the universe, based upon a pile of
unreasonable and false hypotheses, after an existence of over twenty
centuries, sank into oblivion, and was