430 Mr. Wilkins's Account of a Light 
When I saw the light speck, as shewn in the sketch, (see 
Tab. XXL fig. 1.) I was very much surprised; for, at the 
instant of discovery I believed a star was passing over the 
moon, which on the next moment's consideration I knew to 
be impossible. I remembered having seen, at some periods of 
the moon, detached lights from the serrated edge of light, 
through a telescope ; but this spot was considerably too far 
distant from the enlightened part of the moon ; besides, this 
was seen with the naked eye. I was, as it were, rivetted to 
the spot where I stood, during the time it continued, and took 
every method I could imagine to convince myself that it was 
not an error of sight ; and two persons, strangers, passed me at 
the same time, whom I requested to look, and they (may be, 
a little more ignorant than myself) said it was a star. I am 
confident I saw it five minutes at least; but as the time is 
only conjectural, it might not, possibly, be so long. 
The spot appeared rather brighter than any other en- 
lightened part of the moon. It was there when I first 
looked. The whole time I saw it, it was a fixed, steady 
light, except the moment before it disappeared, when its 
brightness increased ; but that appearance was instantaneous. 
I have a reflecting telescope, and as I was very near home, 
I had determined to return and use it on this occasion ; for it 
was so fixed, I had scarcely a doubt but its appearance would 
continue ; but almost at the instant, and whilst I was looking, 
it totally disappeared. You can tell, by the age of the moon at 
that time, the apparent breadth of light upon the surface of 
that body, which, as near as I can judge, determines the dis- 
tance of the spot from two points, B and C, on the periphery 
of the circle, (see fig. 1.) in which A is the enlightened spot ; 
BA = AD = DC; BAD is supposed a right angle. 
