Page:The Moon (Pickering).djvu/100

68 he thought, for perhaps half an hour after the shadow had passed off from the spot. Three different methods of measurement gave for results 0″.82, 0″.73 and 0″.15. At the eclipse of December 16, 1899, the author was more fortunate in the weather, and found an increase in size amounting to 0″.14. The diameter of the spot at this time was only 1″.97 and the duration of obscuration of Linné 2$h$ 29$m$.

The next eclipse which it was possible to observe was that of October 16, 1902. A remarkable increase of size was noted at this eclipse. The obscuration lasted for 2$h$ 26$m$, the minimum size of the spot was 2″. 7, and the enlargement during the eclipse 2″.8. The change in the appearance of Linné due to this enlargement was so great that it was not at first recognised on its reappearance, although the writer was very familiar with the object and its location. Three-quarters of an hour later the Moon was obscured by clouds, but during that interval the spot showed no clear evidence of reduction in size. Four days later, however, the size of the spot was reduced about 1″, preparatory to the final increase preceding sunset.

The eclipse of April 11, 1903, was an unusually dark one. Although not quite total, its magnitude was more than 0.97. At the middle of the eclipse the Moon was one hour above the horizon in Cambridge, and only a segment whose breadth was about half the radius could be seen. Had the eclipse been central, the Moon would have been invisible here. Linn6 was obscured for an hour and a half, reappearing from the shadow at 13$h$ G. M. T. The sky was very hazy at this time, so that the first set of measures following the obscuration was not secured until twenty minutes later. Successive measures seemed to indicate that the spot was diminishing in size.

As compared with the observations made before the eclipse on the previous evening, the enlargement this year, according to my measures, amounted to 0″.55. Of this enlargement, 0″.35 was lost during the first hour and a quarter after the reappearance.

In England many persons having small telescopes are interested in the Moon, and one of these, fortunately, Mr. S. A. Saunder, succeeded in obtaining some measures of Linné upon the night in question. To him the white spot appeared somewhat larger than it did to me, but the interesting feature of his observations is that after the eclipse the spot was found to have increased in size by 0″.50—a result almost identical with that above given.