three days it flared up only to die away again. During these
fluctuations its light varied alternately in the ratio of one to six.
Finally it took a permanent downward course, and after a few months
the naked eye could no longer perceive it; but it remained visible
with telescopes, gradually fading until it had sunk to the ninth
magnitude. Then another astonishing change happened: in August
photographs taken at the Yerkes Observatory and at Heidelberg showed
that the ``nova'' was surrounded by a spiral nebula! The nebula had
not been there before, and no one could doubt that it represented a
phase of the same catastrophe that had produced the outburst of the
new star. At one time the star seemed virtually to have disappeared,
as if all its substance had been expanded into the nebulous cloud, but
always there remained a stellar nucleus about which the misty spiral
spread wider and ever wider, like a wave expanding around a center of
disturbance. The nebula too showed a variability of brightness, and
four condensations which formed in it seemed to have a motion of
revolution about the star. As time went on the nebula continued to
expand at a rate which was computed to be not less than twenty
thousand miles per second! And now the star itself, showing
indications of having turned into a nebula, behaved in a most erratic
manner, giving rise to the suspicion that it was about to burst out
again. But this did not occur, and at length it sunk into a state of
lethargy from which it has to the present time not recovered. But the
nebulous spiral has disappeared, and the entire phenomena as it now
(1909) exists consists of a faint nebulous star of less than the ninth
magnitude.

The wonderful transformations just described had been forecast in
advance of the discovery of the nebulous spiral encircling the star by
the spectroscopic study of the latter. At first there was no