Page:Williamherschel00simegoog.djvu/144

132 on which the All-wise Worker proceeded was his aim and ambition.

Stars had been seen by Flamsteed which Herschel could no longer find. A century had elapsed, and Herschel put these stars down as "lost." He meant that a star thus noted was not to be seen when he looked for it, "but that possibly at some future time, if it be a changeable or periodical star, it may come to be visible again." In other cases he entered in his journal the remark, "Does not exist," when Flamsteed had not himself seen the star. Herschel, however, does not appear to have considered that these "lost stars" may have been comets, or wanderers like his own Uranus, or specks like the numerous body of asteroids and satellites, that were then undiscovered. In a paper written at a later period he found that he had treated as faultless a catalogue of stars which required correction. His conclusions regarding lost or changing stars were thus premature. But neither the poetic beauty nor the possibility of a "lost" star can be denied. Perhaps he was only borrowing a phrase that was used nearly two thousand years earlier by Hipparchus, who, by his catalogue of the fixed stars, gave future generations the means of ascertaining "if stars could be lost and reappear, if they changed their place, their size, their brightness."

Dissatisfied with the principles on which stars visible to the naked eye are classed, according to their brightness, as stars of the first, or second down to the sixth magnitude, he began, about 1782, to adopt a new and more effective but certainly a very laborious method of settling degrees of brightness among the stars, and of determining to what extent