290 REPOKT — 1872. 



but seldom ; the streak a more frequent than y, /3, or ij. Most of the ob- 

 servations during this interval have shown the N.W. part of the floor in 

 proximity with the border as destitute of streaks. 



Interval meridian passage to 168 hours, 



1870, March 17. — Mr. Gledhill recorded the floor as dark, = 0-66 ; he de- 

 scribed the sector and streak a as easy objects, bad as was the night ; the 

 southern streaks were faintest, a and the sector brightest, then came r/, y, ft. 



1870, July 13. — Mr. Gledhill recorded the floor as dark, = 0-G6 ; streaks 

 very bright. 



1870, September 10. — Mr. Elger recorded the sector and trident (three 

 arms, if, e, e) as very distinct, r] scarcely discernible, and ft brightest near 

 the rim, 



&t»i»!fTr?/.— Sun's altitude 40° O'-O to 39° 50'-5 ; tint of floor 0-67 to 

 0'66. Streaks generally visible — the sector and the east and middle arms of 

 trident ; the N.E. streaks less frequent. 



Interval 168 to 156 hours. 



1870, April 16. — Mr. Gledhill recorded the floor as dark,=0-66 ; the streak 

 o is described as bright and sharp. The same evening Mr. EJger writes : — 

 " The markings appeared as on the previous night, with the exception of the 

 projection from Webb's elbow (c), which I could not see." This is note- 

 worthy, as on the 14th and 15th it was evidently increasing, now it seems to 

 have suddenly disappeared ; it does not appear to have been observed by Mr. 

 Gledhill. 



1871, January 7. — Mr. Elger recorded the markings all plain. The curved 

 marking on the N.W. side of floor appeared exactly as shown in the ' Student,' 

 April 1870, p. 161 ; the elbow i was distinctly seen. The new marking p 

 was also well seen ; spots Nos. 5 and 17 were connected by it : at times y 

 seemed to be a prolongation of it ; it could not be traced through the sector. 



The observation by Mr. Elger of k and e with Webb's elbow, being exactly 

 as given in the ' Student,' is interesting, especially as contrasted with the 

 observations, also by Mr. Elger, of the prolongation of the elbow at a sharp 

 angle with a (see ante, pp. 284, 289), from which it may be inferred that the 

 streak is variable in position ; and this gives further countenance to the con- 

 clusion that the N.W. portion of the floor is the most variable. 



1870, August 12. — Mr. Pratt recorded the floor as very dark, Mr. Neison 

 recorded it as dark. Mr. Pratt says : — " In moments of best definition the area 

 comprised between spots Nos. 19, 1, and 4 and the northern and north-east 

 rim was not nearly so well displayed as the rest of the floor, giving a strong 

 impression of an obsciiring medium existing there. The dark parts of the 

 floor were darker near the rim." 



1869, December 19. — Mr. Gledhill recorded the floor as dark, = 0-66 ; the 

 sector very bright, and, after spot No. 1, the most striking object ; a bright, 

 ^, e, ^ less bright ; the prolongation of the sector to spot No. 4 fairly seen. 



1869, September 21.- — Mr. Gledhill recorded the floor as not so dark as the 

 extreme south jiart of the floor of Grimaldi. Of streak c he says, " Spots 

 Nos. 13, 19, and 16 are well seen, a streak of light connects them ; it is a 

 thick, dense streak, not faint and difluse," The sector he describes as 

 " bright, permanent." 



1869, November 19. — Mr. Gledhill recorded the floor as dark, = 0-66. In 

 addition ho gave the following remarks : — " The sector bright and well de- 



