him; the birds have the air, and man and beasts the earth." "So,"
replied the mechanist, "fishes have the water, in which yet beasts
can swim by nature and man by art. He that can swim needs not
despair to fly; to swim is to fly in a grosser fluid, and to fly is
to swim in a subtler. We are only to proportion our power of
resistance to the different density of matter through which we are
to pass. You will be necessarily up-borne by the air if you can
renew any impulse upon it faster than the air can recede from the
pressure."

"But the exercise of swimming," said the Prince, "is very
laborious; the strongest limbs are soon wearied. I am afraid the
act of flying will be yet more violent; and wings will be of no
great use unless we can fly further than we can swim."

"The labour of rising from the ground," said the artist, "will be
great, as we see it in the heavier domestic fowls; but as we mount
higher the earth's attraction and the body's gravity will be
gradually diminished, till we shall arrive at a region where the
man shall float in the air without any tendency to fall; no care
will then be necessary but to move forward, which the gentlest
impulse will effect. You, sir, whose curiosity is so extensive,
will easily conceive with what pleasure a philosopher, furnished
with wings and hovering in the sky, would see the earth and all its
inhabitants rolling beneath him, and presenting to him
successively, by its diurnal motion, all the countries within the
same parallel. How must it amuse the pendent spectator to see the
moving scene of land and ocean, cities and deserts; to survey with
equal security the marts of trade and the fields of battle;
mountains infested by barbarians, and fruitful regions gladdened by