er, as compared
with that of the last, which was well determined, as well as from the
tolerably near coincidence of the intervals of their appearance, we may
suspect them, with Goodricke, to be one and the same star, with a period
of 312 or perhaps of 156 years.' The latter period may very reasonably
be rejected, as one can perceive no reason why the intermediate returns
of the star to visibility should have been overlooked, the star having
appeared in a region which never sets. It is to be noted that, the
period from 945 to 1264 being 319 years, and that from 1264 to 1572 only
308 years, the period of this star (if Goodricke is correct in supposing
the three outbursts to have occurred in the same star) would seem to be
diminishing. At any time, then, this star might now blaze out in the
region between Cassiopeia and Cepheus, for more than 304 years have
already passed since its last outburst.

As the appearance of a new star led Hipparchus to undertake the
formation of his famous catalogue, so did the appearance of the star in
Cassiopeia, in 1572, lead the Danish astronomer Tycho Brahe to construct
a new and enlarged catalogue. (This, be it remembered, was before the
invention of the telescope.) Returning one evening (November 11, 1572,
old style) from his laboratory to his dwelling-house, he found, says Sir
J. Herschel, 'a group of country people gazing at a star, which he was
sure did not exist an hour before. This was the star in question.'

The description of the star and its various changes is more interesting
at the present time, when the true nature of these phenomena is
understood, than it was even in the time when the star was blazing in
the firmament. It will be gathered from that description and from what I
shall have to say farther on about the results of recent observations on
less splendid new stars, that, if this star should reappear in the next
few years, our observers will probably be able to obtain very important
information from it. The message from it will be much fuller and more
distinct than any we have yet received from such stars, though we have
learned quite enough to remain in no sort of doubt as to their general
nature.

The star remained visible, we learn, about sixteen months, during which
time it kept its place in the heavens without the least variation. 'It
had all the radiance of the fixed stars, and twinkled like them; and was
in all respects like Sirius, except that it surpassed Siri