permanence of any particularly white spot or patch, and its 

 movement, if any, relative to the great red spot. 



Explanation of Plate I. 



Fig. I. represents Jupiter's surface on 1870, Jan. 23, 8.20 G.M.T. This 

 is copied from a sketch made by Mr. Joseph Gledhill, and published in 

 Yol. III. of " The Observatory." 



Fig. II. represents Jupiter's surface on 1884, April 21, 5.51 A.M.T. The 

 definition was excellent. The portion of the broad dark belt west of the 

 great hollow was of a deep reddish colour. The curved shading just below 

 the hollow was all that could be seen of the Great Ked Spot. The northern 

 dark belt was considerably split up, and at one place, near the preceding 

 limb was a dusky black spot. Power used 200. 



Fig. III. represents Jupiter's surface on 1885, Feb. 19, 9.45 A.M.T. The 

 definition was excellent. The most striking features were three dark mark- 

 ings on the southern edge of the broad dark belt. The most western was 

 elongated, and the most eastern quite round, like the shadow of a satellite ; 

 the central marking was not so distinct as either of the others though near 

 mid-transit. Two other dark markings were noticeable, one on the northern 

 side of each of the principal belts. Power used 200. 



Fig. IV„ represents Jupiter's surface on 1885, Feb. 21, 10.16 A.M.T. The 

 definition was not very good, except at times. The Red Spot was just going 

 round the preceding limb, but was plainly visible. The dark marking on 

 the south dark belt is the same as the preceding one of the three in the 

 previous sketch. Equatorial light band seemed to consist of a series of 

 festoons. Power used 200. 



Fig. V. represents Jupiter's surface on 1885, March 18, 11.17 A.M.T. De- 

 finition fair. Most noticeable feature, dusky spot on the equatorial belt, as 

 shown. Power used 200. 



Fig. VI. represents Jupiter's surface on 1886, Jan. 22, 13.20 A.M.T. De- 

 finition very good. The Great Red Spot is just going off. The most notice- 

 able feature is the manner in which the south dark belt becomes suddenly 

 fainter to the east of mid-transit. Power used 200. 



Note. — All sketches, except the first, were taken with an 8 inch refractor ; 

 focal length, 9ft. llin. 



