_Shadows cast by Faculæ._—M. Trouvelot, while examining a large sun-spot on May 26, 1878, noticed that it was “completely surrounded by very brilliant and massive faculæ.” “On one part of the penumbra an extraordinary appearance was perceived, which resembled so closely a shadow, as it would have been cast by the overhanging faculous mass, that it seemed useless to seek, and it was impossible to admit, any other explanation. This shadow, the outline of which was a little diffused, had the same shape as, and reproduced with great exactness, the outline of the faculous mass situated above it. It was not so black as the opening in spots called the umbra, but of a very dark tint.” A similar feature was seen by Kirk and Maclean on May 2, 1884, and the ‘Observatory,’ vol. vii. pp. 146, 170, and 197, contains some interesting particulars on this subject. Fig. 24 is a drawing by Kirk, in which the shadow is represented by A, B; at C “it accurately followed the outline of the intensely white margin of the spot.” _Veiled Spots._—The late Father Perry described these objects at the R.A.S. meeting on May 9, 1884, and said they are to be seen all over the face of the Sun. They only exist for two or three minutes, and then disappear. In one instance he observed a train of these veiled spots stretching over “a tenth part of the Sun’s diameter, which was nearly as obvious to the eye as the penumbra of an ordinary spot; it split into two throughout its whole length, and disappeared in a minute. The veiled spots seem to be of two classes: the one appear like small greyish clouds, which disappear after a few minutes, as if they were formed and rapidly evaporated by the Sun’s heat, and the others seem to be connected with the umbra of ordinary spots; they appear about them, and are more permanent than the ordinary veiled spots, lasting sometimes two or three days, but never longer.” These markings appear to have been first detected by Trouvelot in 1875, and he gives some information as to this class of phenomena in the ‘Observatory,’ vol. viii. pp. 228 _et seq._ _Recurrent Disturbances_[14].—It is supposed, and with good evidence affirming the idea, that certain regions of the Sun’s surface are subject to frequent outbursts of spots, which are possibly due to forces acting from below the Sun’s bright atmosphere. After the disappearance of large groups or isolated spots it is therefore advisable to watch the same region for some time afterwards, to find whether it remains perfectly quiescent, or whether it soon again becomes a seat of activity and change.