LORD OXMANTOWN OX THE GREAT NEBULA IN ORION. 
61 
j Remarks on the foregoing Inst. 
Of the existence of all the stars in the foregoing list which are not marked with an H 
I am fully satisfied, and of the remainder I have seen 4 V , 4 VI , 13, 16„ 16 n , 56 x . 
The nebulosity I examined very carefully, and except in a few places I was able to 
verify most of the details. The three rays of nebulosity between the stars 13 x , 16 u , 28, 
39 (Plates II. & III.) I was never able to see well, and on only one occasion did I 
succeed in seeing two of them*. The patches of nebulosity in the region included 
between the stars 25, 56, 79, and 99 I never succeeded in seeing, nor did the rays in the 
region between 133, 142 I? and 149 come out as clearly as represented in the drawing; 
the greater part of the nebulosity on the south and preceding sides of the drawing 
is very faint and ill defined, but the curved outline above 20 is tolerably sharp, and the 
neighbourhood of 20 and 30 x is darker than anywhere in the surrounding parts, even as 
far as 99 x , 37 m , and 1 VII . 
Extreme limits of Nebulosity. 
The distance to which the nebulosity can be traced is very great, but it fades away so 
very gradually that it is quite impossible to assign any definite limit to it. 
M. Liapounov, with an achromatic telescope of 9^ inches aperture, was able to trace 
it up to a line a little beyond 15 through 34, 74, 135, 126, a little outside 135 x near 82, 
46, 6, 4 VI , and 5, and the spiral round 108 f. 
Mr. Bond does not mention the extreme limits to which he was able to trace the 
nebulosity except in two directions. He says, “ The connexion of the main body of the 
nebula with that portion which surrounds C Orionis is traced by the north preceding 
route. It is quite decided,” &c. He also says that the main body of the nebula is not 
connected with C on the following side ; and again, “ I was unable to satisfy myself how 
far it might be possible to trace it (the light) southward, but certainly beyond i. Soon 
after this star it, however, becomes very faint 
His drawing extends to the limits mentioned by Liapounov, and therefore he was 
probably able to trace it rather further on all sides. 
Mr. Lassell, with his reflector of two-feet aperture, did not extend the nebula quite as 
far as Mr. Bond in his drawing, but probably he was able to trace it a good deal further. 
Sir J. Herschel’s drawing in the Cape Observations extends to the stars 6, 124, 145, 
141, 96 x , a point halfway between 5 and 1 XI , and to 34 and 58, and he says (page 29), 
“ The area of the figure (half a square degree in extent) comprises all the nebulous con- 
volutions and appendages which I have been able to trace, with the exception of the 
terminal effusion of the greater proboscis beyond the star A (=135) southwards, which 
may be traced as far as the double star / Orionis, which it involves and renders nebu- 
* Mr. Hunter during the last season sometimes employed the 6-feet telescope as a Herschelian ; I never did 
so ; silvered glass was, however, occasionally substituted for the flat mirror of speculum-metal, which diminished 
the loss of light by the second reflexion, but it soon became dewed and the silver surface broke up. 
f Struve’s Memoir, page 2. 
% Bono’s description of the nebula about 0 Orionis, page 93. 
