us in
brightness and magnitude.' It appeared larger than Jupiter, which was at
that time at his brightest, and was scarcely inferior to Venus. _It did
not acquire this lustre gradually_, but shone forth at once of its full
size and brightness, 'as if,' said the chroniclers of the time, 'it had
been of instantaneous creation.' For three weeks it shone with full
splendour, during which time it could be seen at noonday 'by those who
had good eyes, and knew where to look for it.' But before it had been
seen a month, it became visibly smaller, and from the middle of December
1572 till March 1574, when it entirely disappeared, it continually
diminished in magnitude. 'As it decreased in size, it varied in colour:
at first its light was white and extremely bright; it then became
yellowish; afterwards of a ruddy colour like Mars; and finished with a
pale livid white resembling the colour of Saturn.' All the details of
this account should be very carefully noted. It will presently be seen
that they are highly characteristic.

Those who care to look occasionally at the heavens to know whether this
star has returned to view may be interested to learn whereabouts it
should be looked for. The place may be described as close to the back of
the star-gemmed chair in which Cassiopeia is supposed to sit--a little
to the left of the seat of the chair, supposing the chair to be looked
at in its normal position. But as Cassiopeia's chair is always inverted
when the constellation is most conveniently placed for observation, and
indeed as nine-tenths of those who know the constellation suppose the
chair's legs to be the back, and _vice versa_, it may be useful to
mention that the star was placed somewhat thus with respect to the
straggling W formed by the five chief stars of Cassiopeia. There is a
star not very far from the place here indicated, but rather nearer to
the middle angle of the W. This, however, is not a bright star; and
cannot possibly be mistaken for the expected visitant. (The place of
Tycho's star is indicated in my School Star-Atlas and also in my larger
Library Atlas. The same remark applies to both the new stars in the
Serpent-Bearer, presently to be described.)

[Illustration]

In August 1596 the astronomer Fabricius observed a new star in the neck
of the Whale, which also after a time disappeared. It was not noticed
again till the year 1637, when an observer rejoicing in the name of
Phocyllides Holwarda observed it, and