greatly magnified, but the outline of the sphere on the other side could
not be seen, nor could anything be distinguished in the centre. Both
the outer and inner edges of the crescent were ragged and irregular in
places, and there were faint darker spots on its surface. I called the
doctor's attention to the fact that the ragged appearance was always in
the form of extending teeth on the outer side of the crescent, and in
the form of notches eaten into its inner edge. He studied all these
appearances carefully and finally said,--

"This crescent is that part of Earth which is just coming into morning.
It is gradually shifting from east to west with the Earth's rotation of
course. What we see now, however, is _land_ almost from pole to pole.
There is a small sea just above the middle, which might be the
Mediterranean. Moreover, it must be mountainous land to cause the ragged
edges and the shadows inside."

Then he turned away to get his globe, and I took the place at the
instrument. He was slowly turning the globe and examining it
thoughtfully as he said to himself,--

"The only continuous land from pole to pole with one interrupting sea
must be over the two Americas or over Europe and Africa. The American
mountain ranges run from north to south, while through Europe and Africa
they are scarce, and almost uniformly run from east to west. Besides,
the sand of Sahara would be sure to show as a large, bright, regular
spot. A section from longitude 70 to 80 west would include the Green
Mountains and the Alleghanies of North America and the Andes of South
America, and in that case the darker spot in the centre would be the
Caribbean Sea."

"Look here!" I cried. "Toward the lower end the inner outline is growing
darker but more regular, and faint streaks or shadows reach through the
brighter light toward the dark greenish regular surface which looks like
water."

He observed closely and said,--

"Those shadows must be cast to westward by the enormous peaks of the
Andes, and the dark greenish surface they reach toward must be the
Pacific Ocean."

Then he consulted his globe while I looked. "The first two to come into
view," he said, "would be the two great peaks in Bolivia, over
twenty-one thousand feet high."

"There _are_ two of them together," I said, "and now others are rapidly
coming into view. There are five more scattered unequally, and then,
lower down, three near together."

"Then there is not the slighte