be caused by polar ice and snows. The doctor had expected
such on Mars, and I no longer doubted that this was our objective
planet.

It was like a great holiday for me when the doctor regained
consciousness. Almost as soon as his fever abated he was well enough to
perform his customary duties. His illness had not made him appreciably
weak, because as yet scarcely any effort was required to move about. He
was quite as anxious to hear all my experiences as I was eager to
relate them. I gave him a full account of my struggle passing the
dead-line, of my discovery of Mars, and the various spots I had noted.

"From the time it took the greenish spot to cross, I should judge a
Martian day to be about fifty hours long," I said.

"Then you _must_ have been very lonely," he replied. "For a Martian day
is just forty-one minutes longer than an Earthly day, unless a great
number of our scientists have continually made the same mistake in
observing him."

"When we arrive, we shall be able to determine the point exactly if our
watches commence running again," I answered. "But I think I know one
reason why I have misjudged the time. Ever since you have been ill I
have slept very little. I have hardly felt the need of rest since I lost
my weight. I have been growing more and more wakeful, and I rarely sleep
more than an hour at a time. That seems quite sufficient to refresh me."

"As we regain our weight we shall feel the need of sleep again," he
said. "But on Mars we may need but one-third as much as we had on Earth,
unless we exert ourselves proportionately more."

Then I told him about the circular spot which had seemed to slip off the
upper edge of Mars, and asked his explanation of it.

"That must have been Phobos, one of the moons of Mars," he said.

"One of his moons!" I exclaimed; "I didn't know he had _any_."

"You are an American, and say that!" he answered in surprise. "It is one
of the astronomical glories of your people that they discovered the two
moons of Mars, during the favourable opposition of 1877."

"This is the first case I remember where we have left it to a foreigner
to tell us how great we have been!" I laughed.

"These two moons of Mars also furnish a most interesting example of how
fiction may forestall and pre-figure actual scientific discovery. Dr.
Swift made Gulliver, in his wonderful travels, discover two moons of
Mars, revolving at a speed which he must have thought ridiculously fast.
Many yea