The true study of meteoric astronomy may be said to date from the year 1833, when a shower of most extraordinary splendour was witnessed. The magnificence of this display was the means of turning greater attention to the subject; and it was observed as a fact, though the importance of the observation was scarcely realized, that the meteors all appeared to come from nearly the one point in the constellation Leo. The fact of there being a single radiant point implied that the meteors were all moving in parallel lines, and had entered our atmosphere from a vast distance. Humboldt, who had witnessed a previous appearance of this shower in 1799, suggested that it might be a periodic phenomenon; and his suggestion was amply confirmed when in 1866 the shower made its appearance again in scarcely diminished splendour. Gradually other showers came to be recognised, and their radiant points fixed; and meteoric astronomy began to be established upon a scientific basis. In 1866 Schiaparelli announced that the shower which radiates in August from the constellation Perseus follows the same track as that of Swift's comet (1862 iii.); and in the following year the great November shower from Leo, already alluded to, was proved to have a similar connection with Tempel's comet (1866 i.). The shower which comes from the constellation Lyra, about April 20, describes the same orbit as that of Comet 1861 i.; while, as already mentioned, the mysterious disappearance of Biela's comet received a reasonable explanation by its association with the other great November shower--that which radiates from the constellation Andromeda. With regard to the last-named shower, it has not only been shown that the meteors are associated with Biela's comet, but also that they separated from it subsequent to 1841, in which year the comet's orbit was modified by perturbations from Jupiter. The Andromeda meteors follow the modified orbit, and hence must have been in close association with the comet when the perturbation was exercised.