el was a still more rare possession. It was,
therefore, to be expected that, if such previous observations existed,
they would merely record Uranus as a star visible, and indeed bright, in
a moderate telescope, but still not claiming any exceptional attention
over thousands of apparently similar stars. Many of the early
astronomers had devoted themselves to the useful and laborious work of
forming catalogues of stars. In the preparation of a star catalogue, the
telescope was directed to the heavens, the stars were observed, their
places were carefully measured, the brightness of the star was also
estimated, and thus the catalogue was gradually compiled in which each
star had its place faithfully recorded, so that at any future time it
could be identified. The stars were thus registered, by hundreds and by
thousands, at various dates from the birth of accurate astronomy till
the present time. The suggestion was then made that, as Uranus looked so
like a star, and as it was quite bright enough to have engaged the
attention of astronomers possessed of even very moderate instrumental
powers, there was a possibility that it had already been observed, and
thus actually lay recorded as a star in some of the older catalogues.
This was indeed an idea worthy of every attention, and pregnant with the
most important consequences in connection with the immortal discovery to
be discussed in our next chapter. But how was such an examination of the
catalogues to be conducted? Uranus is constantly moving about; does it
not seem that there is every element of uncertainty in such an
investigation? Let us consider a notable example.

The great national observatory at Greenwich was founded in 1675, and the
first Astronomer-Royal was the illustrious Flamsteed, who in 1676
commenced that series of observations of the heavenly bodies which has
been continued to the present day with such incalculable benefits to
science. At first the instruments were of a rather primitive
description, but in the course of some years Flamsteed succeeded in
procuring instruments adequate to the production of a catalogue of
stars, and he devoted himself with extraordinary zeal to the
undertaking. It is in this memorable work, the "Historia Coelestis" of
Flamsteed, that the earliest observation of Uranus is recorded. In the
first place it was known that the orbit of this body, like the orbit of
every other great planet, was inclined at a very small angle to the
ecl