254 Mr. Baily on an [Oct. 



It is hoped, therefore, that the attention of astronomers will be 

 more drawn towards this subject in the ensuing eclipse.* 



In the eclipse of 1737, Maclaurin observes that about 20 

 seconds " before the annulus was complete, a remarkable point 

 or speck of pale light appeared near the middle of the part of the 

 moon's circumference that was not yet come upon the disc of 

 the sun ; and a gleam of light, more faint than that point, 

 seemed to extend from it to each horn." 



In the eclipse of 1748, it was noticed that there was " about 

 the middle of the eclipse, a remarkably large spot of light, of an 

 irregular figure, and of a considerable brightness, about seven or 

 eight minutes within the limb of the moon." Mr. Short states 

 that this eclipse was not quite annular at Aberdour Castle : " the 

 cusps seemed to want about ± of the moon's circumference to be 

 joined, yet a brown light was plainly observed both by my Lord 

 Morton and myself to proceed or stretch along the circumfe- 

 rence of the moon, from each of the cusps, about ^ of the whole 

 distance of the cusps from each cusp ; and there remained about 

 4- of the whole distance of the cusps not enlightened by this 

 brown light." — " I observed at the extremity of this brown light, 

 which came from the western cusp, a larger quantity of light 

 than in any other place, which at first surprised me ; but after- 

 wards I imagined it must have proceeded from some cavity or 

 valley made by two adjoining mountains on the edge or limb of 

 the moon. I had often formerly observed mountains on the 

 circumference of the moon, more or less every where round it, 

 but never saw them so plain as during the time of this eclipse. 

 The mountainous inequalities on the southern limb of the moon 

 were particularly remarkable ; in some parts mountains and 

 valleys alternately ; others extended a considerable way along 

 the circumference and ended almost perpendicularly like a pre- 

 cipice. My Lord Morton was able to see them very easily 

 through his small reflector." 



The King of France, who (as already mentioned) went pur- 

 posely to Compiegne to observe this eclipse, discovered towards 

 the middle of the eclipse (which was not more than 9^ digits) 

 " sur la surface de la lune, comprise entre les cornes du soleil, 

 des rayons de lumiere rouges, et un filet de lumiere qui sembloit 

 masquer le disque de la lune, et qui s'etendoit a, une distance 

 des cornes. f " 



M. De LTsle, in his publication above alluded to, seems to 

 think that a quick eye, guarded with a sufficiently dark glass, 



* See Lalande's Astronomie, vol. ii. p. 445; Delambre's Astronomie, vol. ii* 

 p. 423; and also M. Le Monnier's memoir Sur les Eclipses totales du Soleil, in the 

 Mem. de I'Acad. des Sciences for 1781, p. 243. In this memoir there is a map of 

 the path of the moon's umbra in the total eclipse of May 22, 1724, and which up. 

 pears to have proceeded over great part of England : nevertheless 1 cannot find 

 any observation «f it in this country. 



t Mem, de I'Acad. Roy. des Sciences, 1748, p. 56. 



