32

OBSERVATIONS OF

of the two figures: and. to suppose it seen as in 1837, and yet drawn as in 1824, would arguemore negligence than I can believe myself fairly chargeable with.

(68) There is another point on which considerable stress might be laid, were I satisfiedthat the earlier diagrams on which it turns were done with sufficient care. In 1837, thenebulous spur towards the end of the great proboscis, which terminates at E (No. Ill),certainly was neither joined to the proboscis itself, nor directed towards the star A (No. 135),but rather towards a point about one-third of the distance from A (No. 135), to C (No. 126),near to where there is a small star 16m (No. 131). Now I find two diagrams, one of December25, 1832, the other of November 25, 1834, in which this spur is represented as running directlyfrom A to E, and forming a complete hook, no way disjoined from the proboscis. But thechief attention on the first of these occasions was directed to the magnitudes and situationsof the stars, and the hook seems to have been only roughly sketched in as a novelty to befurther noticed in future, while on the last it is only very faintly indicated, in a diagram ofthe stars adjacent to 0 Orionis on all sides, preparatory to the formation of chart intended totake in both i Orionis on the one side and C Orionis on the other, which was subsequentlydiscontinued.

(69) Still less can we insist, as evidences of change, on such particulars as the curiouslynotched outline of the “ Nebula Mairanni” about the star p (No. 108), now for the first timerepresented; or on the intricately rifted and broken state of the frontal and occipital regionof the principal nebula. I ought to mention here that (owing no doubt to the difficulty ofproperly representing on paper and by lamp-light an object of the kind, I find a good deal ofdisagreement in respect of the number, size, and distribution of the portions into which it maybe considered as broken up, not only between my present figure and Dr. Lamont’s, butbetween my own drawings of this part on several nights. But the most material differencebetween Dr. Lamont’s figure and mine consists in the characteristic forms of these portions,which he represents as rounded masses more or less detached from or running into each otherand into a general nebulous ground ; while in all my later drawings the effect is rather that ofa tolerably uniform surface marked with branching rifts or channels, like roads. There is onepeculiarity in Dr. Lamont’s figure which I can no way reconcile to my own impressions; viz.,the strangely different form and magnitude which he assigns to the “ Sinus Gentilii,” fromwhat I have always found it. This is a point which I trust he will be induced to re-examine.

(70) i] Argus and the great Nebula surrounding it.

Plate IX. r, Argus = h. 3295 = A. 309 = Lac. 968 = Brisb. 3198. R A. 10° 38' 38"N P D 148° 47'.

There is perhaps no other sidereal object which unites more points of interest than this.Its situation is very remarkable, being in the midst of one of those rich and brilliant masses,a succession of which curiously contrasted with dark adjacent spaces (called by the oldnavigators coal-sacks), constitute the milky way in that portion of its course which lies betweenthe Centaur and the main body of Argo. In all this region the stars of the milky way arewell separated, and, except within the limits of the nebula, on a perfectly dark ground, and on