next; as, the Universal Medicine, which will certainly cure all that
have it; the Philosopher's Stone, which will be found out by Men that
care not for Riches: the transfusion of young Blood into old Men's
Veins, which will make them as gamesome as the Lambs, from which 'tis to
be derived; an Universal Language, which may serve all Men's Turn, when
they have forgot their own: the Knowledge of one another's Thoughts,
without the grievous Trouble of Speaking: the Art of Flying, till a Man
happens to fall down and break his Neck: Double-bottom'd Ships, whereof
none can ever be cast away, besides the first that was made: the
admirable Virtues of that noble and necessary Juice called Spittle,
which will come to be sold, and very cheap, in the Apothecaries' Shops:
Discoveries of new Worlds in the Planets, and Voyages between this and
that in the Moon, to be made as frequently as between York and London:
which such poor Mortals as I am think as wild as those of Ariosto, but
without half so much Wit, or so much Instruction; for there, these
modern Sages may know where they may hope in Time to find their lost
Senses, preserved in Vials, with those of Orlando.'

Both Sir William Temple and Joseph Glanvill were men of acute
intelligence and complete sanity; the one an aged statesman deeply
versed in the deceits and follies of men; the other a young cleric,
educated in the Oxford of the Commonwealth, and stirred to enthusiasm by
what he had there heard of the progress of natural philosophy. In this
perennial debate the man of the world commonly triumphs; he plays for
the stakes that are on the table, and does not put faith in deferred
gains. For something like two hundred years Sir William Temple's triumph
was almost complete. Now things have changed, and Glanvill's rhapsody
comes nearer to the truth. Wireless telegraphy, radium, the discoveries
of bacteriology, and not least the conquest of the air, have taken the
edge off the sallies of the wit, and have verified the dreams of the
prophet.

What most delayed the science and art of flight, which made no progress
during the whole of the eighteenth century, was an imperfect
understanding of the flight of birds. The right way to achieve flight,
as events were to prove, was by the study and practice of gliding. But
birds were believed to support, as well as to raise, themselves in the
air chiefly by what in the jargon of science is called orthogonal
flight, that is, by direct downwar