EARL ROSSE’S OBSERVATIONS ON THE NEBULAi:. 
513 
March 7, 1848. — (6-feet telescope). — Night bad : aurora. Darkness in the centre ; 
star not certainly seen ; outline ragged. 
March 11, 1848.— Seen by Dr. Robinson and my former assistant, Mr. Rambaut; 
sketch made of it. “Two stars considerably apart in the central region; dark 
penumbra around each spiral arrangement, with stars as apparent centres of attrac- 
tion ; stars sparkling in it, resolvable ; night excellent.” Note by Mr. Rambaut : 
“March 5, 1848. — Saw two dark and very large spots in the middle; Lord Rosse 
remarked that all round its edge the sky appeared darker than the average.” 
“March 11, 1848. — Remarkably fine night ; a brilliant star in the centre ; also star 
to the right ; round each a black space (see sketch).” Note by Mr. Rambaut: “ March 
25, 1848. — Air steady, but slight haze ; large star visible. Only at one clear interval 
could I get a glimpse of the spiral arrangement of this nebula, which I should have 
totally overlooked had I not seen it so plainly on a former occasion. 
“March 26, 1848. — Second bright star visible; spiral arrangement hardly per- 
ceptible ; not seen so well as on the 11th of March. 
“March 27, 1848. — Not seen so well as last night; second star seen at rare in- 
tervals, power 468. 
“March 28, 1848. — Night hazy, could not see second star.” 
“March 31, 1848. — Caught one glimpse of second star, but saw the large star 
very plainly. 
“April 1, 1848. — Night hazy; spiral arrangement little more than suspected; ne- 
bula very faint. 
“April 3, 1848. — Small star distinctly seen; spirals tolerably well brought out; 
hazy, but air steady. 
“April 6, 1848. — First star seen easily, though hazy ; the second only occasionally ; 
spiral arrangement hardly discernible. 
“January 1850. — Seen very imperfectly; only one of the stars seen. 
“March 9, 1850. — Second star only seen for a moment.” Several attempts were 
made to procure measures of position and distance of the two stars this spring, but 
in vain, the season was so unfavourable. In 1848, the micrometer requiring illumi- 
nation, no attempt was made. With the micrometer as at present mounted there 
would not have been the slightest difficulty in procuring measures. 
Fig. 12, H. 464. — “Annular nebula at the edge of the cluster M. 46. Sketched 
Deeember 22, 1848 annular, two stars in it. 
“January 27, 1849. — A third star suspected in brightest part. 
“January 29, 1849. — Third star strongly suspected. 
“February 13, 1849. — Observed, nothing further. 
“March 16, 1849. — Saw but two stars in it.” 
Fig. 13, H. 2241. — “ October 31, 1848. — Has a central spot, at moments very dark. 
“Deeember 13, 1848. — Nothing more, except perhaps that faint external annulus 
extends further than had been seen before. 
3 u 
MDCCCL. 
