September 1th, 1820. 39 



portion of the surrounding surface. It was not, however, one 

 uniform diffusion of light, but divided into several streams of 

 unequal extent and brightness ; separated apparently by- ine- 

 qualities, running in nearly continuous ridges. Towards the 

 inner extremities of the enlightened portion, the dark summits 

 of these ridges rising above the surrounding splendour, pre- 

 sented to the eye, irregular, or rather undulating, lines of shade. 

 Along the circumference, on the contrary, where the light was 

 more powerful, the tops of these mountainous inequalities ap- 

 peared like dotted lines of very brilliant spots, but no where 

 did they shew as insulated or scattered points. This appear- 

 ance continued for upwards of half a minute, and seemed 

 gradually to decrease, apparently at one time shooting nearly at 

 right angles from the body of the moon towards the west, as if 

 deflected from the spherical surface. This, however, not being 

 well ascertained, is not represented in the annexed sketch. 



A very singular circumstance connected with these moun- 

 tains, is, that during the former part of the eclipse, they were 

 most conspicuous on the lower or western portion of the lunar 

 circumference ; but from a few seconds after the central con- 

 junction, they continued to be most remarkable on the eastern or 

 upper circumference, to the end of the eclipse. At the time of 

 greatest obscuration they were rather indistinct, the cmtline ap- 

 pearing to melt into the surrounding light ; but this was of 

 80 short duration as to be scarcely more than just perceptible. 



At the conclusion of this phenomenon, when the moon was 

 just on the point of receding from the sun, no elongation of their 

 margins, as mentioned in other instances, was observed, but 

 the circumference of the moon was less distinctly marked, and 

 for a few moments the motion seemed to be suspended, the 

 moon appearing as it were to adhere to the surface of the sun ; 

 one small triangular portion at length only remained, which dis- 

 appeared, not gradually, but at once, the light bursting from 

 between as if forcing the luminaries apart. 



