Page:The story of the comets.djvu/253

XIII. scattered cluster points must have been of great antiquity, since the interval of 12 years between the years 855–56 and the next display in 868 differs very much from the distance found to separate in modern times the well-marked minor apparitions of the years 1787, 1820, and 1822 compared with the modern appearances of the chief group in 1799 and 1833. It may, therefore, be assumed that important consequences may sooner or later be expected to be traced as the outcome of investigations in this field of cosmical phenomena, for it cannot be supposed that we have reached yet by a long way the end of our tether in our knowledge of these subjects. The next return of the Leonid meteor-comet is expected in the summer of 1932.

It was subsequently found that the meteor shower belonging to the date of April 20, and now known as the Lyrids, matched, as regards their orbit, the Comet of 1861 (i.), whilst the shower of Nov. 27, now known as the Andromedes, similarly matched the orbit, as known up to that date, of the missing Comet of Biela. There is not much to be said about the Lyrids and their attached comet, but as regards the Biela association a long tale can be unfolded.

When things had reached the stage of developement which has just been described, it naturally came into men's minds, could the newly-acquired knowledge be brought to bear in any way in elucidating the mystery of the disappearance of Biela's Comet, which at that time was an unprecedented and wholly inexplicable mystery? It was possible to give an affirmative answer to the question. Though this comet had failed to appear either in May 1859, or in Jan. 1866, hopes were entertained that it might be picked up when next due, which would be in Aug. and Sept. 1872, the perihelion passage having been fixed for Oct. 6. These hopes were not realised, but the appearance on Nov. 27, 1872, of an abundant meteor shower corresponding in the position of its radiant point, and in the date of its appearance, with the position and date of a meteor