In 1670, 1848, and 1860 temporary stars made their appearance, but none of them was of great brilliance. In 1866 one of the second magnitude broke forth in the “Northern Crown” and awoke much interest, because by that time the spectroscope had begun to be employed in studying the composition of the stars, and Huggins demonstrated that the new star consisted largely of incandescent hydrogen. But this star, apparently unlike the others mentioned, was not absolutely new. Before its outburst it had shown as a star of the ninth magnitude (entirely invisible, of course, to the naked eye), and after about six weeks it faded to its original condition in which it has ever since remained. In 1876 a temporary star appeared in the constellation Cygnus, and attained at one time the brightness of the second magnitude. Its spectrum and its behavior resembled those of its immediate predecessor. In 1885, astronomers were surprised to see a sixth-magnitude star glimmering in the midst of the hazy cloud of the great Andromeda Nebula. It soon absolutely disappeared. Its spectrum was remarkable for being “continuous,” like that of the nebula itself. A continuous spectrum is supposed to represent a body, or a mass, which is either solid or liquid, or composed of gas under great pressure. In January, 1892, a new star was suddenly seen in the constellation Auriga. It never rose much above the fourth magnitude, but it showed a peculiar spectrum containing both bright and dark lines of hydrogen. But a bewildering surprise was now in store; the world was to behold at the opening of the twentieth century such a celestial spectacle as had not been on view since the times of Tycho and Kepler. Before daylight on the morning of February 22, 1901, the Rev. Doctor Anderson, of Edinburgh, an amateur astronomer, who had also been the first to see the new star in Auriga, beheld a strange object in the constellation Perseus not far from the celebrated variable star Algol. He recognized its character at once, and immediately telegraphed the news, which awoke the startled attention of astronomers all over the world. When first seen the new star was no brighter than Algol (less than the second magnitude), but within twenty-four hours it was ablaze, outshining even the brilliant Capella, and far surpassing the first magnitude. At the spot in the sky where it appeared nothing whatever was visible on the night before its coming. This is known with certainty because a photograph had been made of that very region on February 21, and this photograph showed everything down to the twelfth magnitude, but not a trace of the stranger which burst into view between the 21st and the 22nd like the explosion of a rocket.