15] ON THE TOTAL ECLIPSE OF THE SUN, JULY, 1851. 83 



last rays had disappeared. At the point nearly opposite, or about 105 

 from the upper point of the Moon, measured towards the west, I noticed 

 a rosy-coloured prominence, about one minute in altitude. The upper or 

 northern boundary of this was well denned, and had nearly the form of a 

 quadrantal arc of a circle meeting the Moon's limb perpendicularly, the con- 

 cavity being turned downwards ; the southern boundary was also somewhat 

 concave downwards, but the illumination near it was less, and diminished 

 gradually, so that it was difficult to ascertain its exact form. The appearance 

 was somewhat like the enlightened portion of a hemispherical mountain 

 standing on the Moon's limb and illuminated on its northern side, whilst 

 more than half the hemisphere on the opposite side was invisible. After 

 watching this for a short time, I observed that its altitude was gradually 

 increasing, and my attention became in consequence entirely engrossed by 

 it. The southern boundary of this prominence soon became better defined 

 than at first, while the northern boundary remained perfectly even and well 

 defined throughout. The altitude continued to increase till the moment of 

 the Sun's reappearance, when it amounted to nearly three minutes. The 

 form of the prominence now resembled that of a sickle, and it projected 

 nearly perpendicularly from the Moon's limb, the part nearest the Moon 

 being nearly straight, but the curvature gradually increasing in approaching 

 the point, which was sharp and turned downwards. The breadth at the 

 base was, perhaps, two-thirds of a minute. There was no sensible, or at 

 any rate, no marked change of form in the several parts after they had 

 once been seen, but only a gradual lengthening by additions at the base, 

 of such a kind as would have been occasioned by the motion of the Moon 

 if the prominence had really belonged to the Sun 1 . My impression, how- 

 ever, is, that the increase of length was greater than can be accounted 

 for by the Moon's motion, and that it proceeded more rapidly towards the 

 end of the totality than at first, but I cannot feel certain on this point. 

 A little before the end of the totality, the corona seemed to become brighter 

 in the neighbourhood of the prominence, which was close to the point 



1 " While the Sun is totally covered by the Moon, the latter appears surrounded by a 

 luminous ring, with rays proceeding from it, something in the manner of the glory which 

 is placed by painters round the heads of saints. The most extraordinary appearances how- 

 ever were certain rosy-coloured flame-like projections from the limb of the Moon, one, which 

 I noticed particularly, was very large. This was at the point of the limb at which the Sun 

 reappeared, and it appeared gradually to lengthen out as the Sun's limb was approaching the 



Moon's, as if it had really been connected with the Sun and moved with it If these 



rosy flames really belong to the Sun, they must be of enormous magnitude, the one I noticed 

 could not have been less than 50,000 miles in length." From Letter written Aug. 9, 1851. 



112 



