But after
a time it extended visibly beyond the boundary of the halo itself, and
I perceived that the edge of the Sun's disc had come at last into
view. It was but a minute and narrow crescent, but was well worth
watching. The brightening and broadening of the halo at this point I
perceived to be due, not to the Sun's effect upon the atmosphere that
produced it, but chiefly to the twilight now brightening on that limb
of the Earth's disc; or rather to the fact that a small portion of
that part of the Earth's surface, where, if the Sun were not visible,
he was but a very little below the horizon, had been turned towards
me. I saw through the telescope first a tiny solar crescent of intense
brightness, then the halo proper, now exceedingly narrow, and then
what looked like a silver terrestrial crescent, but a mere thread,
finer and shorter than any that the Moon ever displays even to
telescopic observers on Earth; since, when such a minute portion of
her illuminated surface is turned towards the Earth, it is utterly
extinguished to our eyes by the immediate vicinity of the Sun, as was
soon the case with the terrestrial crescent in question.
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