480 Prof. Phillips Notice of a Spot on the Sun. [Nov. 23, 



form, and has a bright central speck, with a rather obscure narrow prolon- 

 gation. The smaller umbra is tripartite, and has small gleaming points in 

 it. Several black dots in the surrounding surface, amidst faculae, areolse, 

 and other structures very distinctly seen for a great part of this day with 

 good definition (PL XL fig. 4). 



Nov. 13, 9.45. Very great change in general figure and in the several 

 parts of the spot. The larger spot is now cut in twain ; the smaller spot 

 is reduced to two dots, surrounded by a large bright space. The spot is 

 now about 36 from the limb (PI. XI. fig. 5). 



Nov. 15. The spot is very near the edge, and of course almost elliptical 

 in outline (PL XI. fig. 6). The faculse which accompany it are seen on a 

 smaller scale in PL XI. fig. 7. 



The woodcut shows the apparent places of the spot at the several dates 

 mentioned. 



EXPLANATION OF THE FIGURES IN PLATES X., XI., XII. 



PI. X. fig. 1. Appearance of spot near the edge of the disk before passing off. 



2. Spot after reappearance, within the opposite edge of the disk. 



3. The same farther on the disk. 



PI. XI. fig. 4. The same after passing the centre of the disk. 



5. The same advancing toward the edge. 



6. The same very near the edge. 



7. The same surrounded by faculaj. This figure is drawn on a smaller 



scale than the others. 



PI. XII. figs. 1, 2, 3, 4, 5. Sketches taken in October 1865. 

 6. Sketched in April 1864. 



