Page:Popular Science Monthly Volume 76.djvu/24

20 The prediction for the next return was taken in hand, in due time, by no less than four distinguished mathematicians—Damoiseau, Pontécoulant, Lehmann and Rosenberger. These found, respectively, for the time of perhelionperihelion [sic] passage, 1835, November 4, 13–15, 26 and 12. This time the perturbations due to Uranus and the earth were included as well as those of Jupiter and Saturn. The actual time proved to be November 16.

Search for the comet began, on the part of numerous comet seekers, as early as January, 1835, but the first sight of it was obtained August 5, by Dumorchel, at Rome, very near the predicted place. About the middle of September, two months before perihelion, it became visible to the naked eye. The greatest brilliancy occurred about the middle of

October. The public had been expecting something very striking, but, unfortunately, cloudy weather interfered to a great extent. It practically disappeared from the northern hemisphere with perihelion passage, but was followed for some time longer by Sir John Herschel at the Cape of Good Hope.

As regards the present appearance, the comet is already with us. The preliminary searching on this occasion has been greatly facilitated by photography, a resource not available on previous occasions. More than a year ago, as soon as this region of the sky had fairly emerged from the sun's rays, the campaign began at a number of observatories, in this country and Europe. The results were negative. Dr. Wolf, of Heidelberg has the honor of being the first to detect the comet on one