The first Nova, of which we have a really scientific record, was the star which suddenly blazed out, in November, 1572, in the familiar W of Cassiopeia. It was carefully observed by the great astronomer, Tycho Brahé, and, according to him, was brighter than Sirius, Alpha Lyræ, or Jupiter. Tycho followed it till March, 1574, by which time it had sunk to the limit of unaided vision, and further observation became impossible. There is at present a star of the eleventh magnitude close to the place fixed for the Nova from Tycho's observations. In 1604 and 1670, new stars were observed, the first by Kepler and his assistants, the second by the monk Anthelme; but from 1670 there was a long break in the list of discoveries, which was ended by Hind's observation of a new star in Ophiuchus (April, 1848). This was never a very conspicuous object, rising only to somewhat less than fourth magnitude, and soon fading to tenth or eleventh. We can only mention the 'Blaze Star' of Corona Borealis, discovered by Birmingham in 1866, the Nova discovered in 1876 by Schmidt of Athens, near Rho Cygni--an object which seems to have faded out into a planetary nebula, a fate apparently characteristic of this class of star--and the star which appeared in 1885, close to the nucleus of the Great Nebula in Andromeda. In 1892, Dr. Anderson of Edinburgh discovered in the constellation Auriga a star which he estimated as of fifth magnitude. The discovery was made on January 31, and the new star was found to have been photographed at Harvard on plates taken from December 16, 1891, to January 31, 1892. Apparently this Nova differed from other temporary stars in the fact that it attained its full brightness only gradually. By February 3 it rose to magnitude 3·5, then faded by April 1 to fifteenth, but in August brightened up again to about ninth magnitude. It is now visible as a small star. The great development of spectroscopic resources brought this object, otherwise not a very conspicuous one, under the closest scrutiny. Its spectrum showed many bright lines, which were accompanied by dark ones on the side next the blue. The idea was thus suggested that the outburst of brilliancy was due to a collision between two bodies, one of which, that causing the dark lines, was approaching the earth, while the other was receding from it. Lockyer considered the conflagration to be due to a collision between two swarms of meteorites, Huggins that it was caused by the near approach to one another of two gaseous bodies, while others suggested that the rush of a star or of a swarm of meteorites through a nebula would explain the facts observed. Subsequent observations of the spectrum of Nova Aurigæ have revealed the fact that it has obeyed the destiny which seems to wait on temporary stars, having become a planetary nebula.