the attraction of these larger masses. Mars has merely, in the course of
time, cleared for itself a broad path in its yearly journey and is now
encountering no more straggling fragments."

"There, Doctor," said I, "you are well answered. And now, Thorwald, tell
us how you have escaped other evils, famine and fire for instance."

"Fire," continued our friend, "was one of the first foes subdued. We quite
early learned to make our habitations and everything about us of fireproof
materials, and, if I mistake not, you on the earth will not long endure an
enemy which can be so easily put down. You will find all materials can be
so treated with chemicals as to be absolutely safe from the flames. We
have fire only when and where we desire it.

"When you speak of famines you touch a more difficult subject, but here,
too, time and skill have wrought wonderful changes. In our histories we
read of the time when the weather was chiefly noted for its fickleness,
and when some parts of our globe were mere desert wastes, where rain was
unknown and no life could exist. And in the inhabited portions one section
would often be deluged with too much rain while another would have none,
both conditions leading to a failure in agriculture and much consequent
suffering. A long time was spent in gathering statistics, which finally
proved that if the rainfall were distributed there would be just about
enough to water sufficiently the whole surface of the globe. Nature
provided rain enough, but it did not always fall where and when it was
most needed. It seemed to be left with us to find a remedy for this
apparent evil. When I say 'us' in this way I mean our race as a whole, for
most of these changes took place many ages ago.

"Our philosophers had seen so many difficulties removed and improvements