34 2 Mr. Schroeter's Observations 
There can hence be no doubt of the termination of the cusp 
being at c : and this being well ascertained, I now distin- 
guished with the greatest certainty the twilight extending 
from c to k . The most remarkable circumstances attending 
this light were, that it was broadest and brightest at c, and 
that it dwindled away and contracted towards k, where it lost 
itself in the faint glimmering of our terrestrial light ; and that 
at the northern cusp, fig. 2, at which there do not appear to 
be so many mountains and inequalities as at the southern, this 
light exhibited the same pyramidal form, and was of equal 
length, and alike fading in intensity and colour, as that at the 
southern. 
This light, compared with that of the thinnest and least 
bright part of the cusp d c, was as faint as the pale ash- 
coloured spots in the luminous hemisphere, when opposed 
to the bright ones. But this is still better illustrated by a 
comparison between the high mountain /, fig. 1, which now 
already appeared illuminated by the solar light, and the spot 
Aristarchus, which shone moderately merely with the light 
reflected from our globe. The said mountain had, compa- 
ratively with the thin luminous arc d ef of the bright he- 
misphere, and the mountains g, h, i, c, a very pale, fading, but 
yet brighter light than Aristarchus, as indeed might have 
been expected from what I said in my Selenotop. Fragm. ; but 
this reflected light upon Aristarchus was however sensibly 
brighter than the glimmering light from c to k . And respect- 
ing the still fainter terrestrial light which bordered the lu- 
minous curve from c to k, fig. 1 and 2, I cannot give a better 
idea of it than by observing, that the light at the extremities of 
both the cusps appeared of a pyramidal form, similar to, but 
