274 



REPORT 1872. 



the present series of observations, occurred on Nov. 15, 1869, interval 84 to 96 

 hours. See also December 13, 1869, interval 48 to 60 hours, p. 278, when 



Fig, 11. 



Plato, January 12, 1870.— T. G. E. Elger. 



Mr. GledhiU recorded the N. and N.W. parts of the floor as brightest. On De- 

 cember 14, 1869, interval 72 to 84 hours, Mr. Elger sketched a and " o," with 

 Webb's elbow, the west side of which merged into the streak " o." The streak 

 c seen by Mr. Glcdhill and the spots Nos. 13, 19, and 16 were not seen. Mr. 

 GledhiU mentioned the bright floor connecting a and 2 without a distinct streak. 

 The next day, Dec. 15, interval 96 to 108 hours, the elbow is not separately 

 given ; the two sketches (see figs. 11 and 13) very much resemble those of 

 January 12 and 14, 1870. The state of the N.W. part of the floor was nearly 

 similar during the two lunations, the greatest amount of light being observ- 

 able at the earlier epoch in both cases. Mr. GledhiU noticed the N.W. part 

 of the floor bright on January 11, interval 36 to 48 hours. In Mr. Elger's 

 diagram of Sept. 20, 1869 {ante, p. 263), he gives three Ught markings — the 

 sector h, the middle arm of the trident e, and a straight marking on the N.W., 

 replacing the curved streak c of Pratt of August 1869. The western branch 

 of this streak appears to be connected with spot No. 19. To distinguish it 

 from h, which crosses it, it is designated " o ; " the eastern portion which 

 joins the N. border is a. On December 20, 1869, interval 144 to 132 hours, 

 the floor was approaching its normal state. 



1870, March 11. — Mr. GledhiU recorded the floor as "medium, =0*50, 

 like the tint of the Mare Frigoris." 



1870, February 9, 4.45. — Mr. GledhiU described the floor east of a line 

 through spots Nos. 1 and 3, produced both ways, as " dusky." At 7 hours 

 Mr. GledhiU writes, " E. part of floor still dusky as far as the east edge of 

 sector, and a Une along this edge produced to the north border." 



Strealcs coming into sunlight. — 1870, February 9, 5.40. Sector seen faint, 

 but easy. Streak a seen as a sharp, narrow, bright streak, running from the 

 tip of the most northern shadow across to the N.E. border; it is nearly 



