liquid fire." This was written in the thirteenth century, and
it is scarcely edifying to find four hundred years after this
the Jesuit Father Lana, who contrived to make his name live in
history as a theoriser in aeronautics, arrogating to himself
the bold conception of the English Friar, with certain
unfortunate differences, however, which in fairness we must
here clearly point out. Lana proclaimed his speculations
standing on a giant's shoulders. Torricelli, with his closed
bent tube, had just shown the world how heavily the air lies
above us. It then required little mathematical skill to
calculate what would be the lifting power of any vessel void of
air on the earth's surface. Thus Lana proposed the
construction of an air ship which possibly because of its
picturesquesness has won him notoriety. But it was a fraud. We
have but to conceive a dainty boat in which the aeronaut would
sit at ease handling a little rudder and a simple sail. These,
though a schoolboy would have known better, he thought would
guide his vessel when in the air.

So much has been claimed for Father Lana and his mathematical
and other attainments that it seems only right to insist on the
weakness of his reasoning. An air ship simply drifting with the
wind is incapable of altering its course in the slightest
degree by either sail or rudder. It is simply like a log borne
along in a torrent; but to compare such a log properly with the
air ship we must conceive it WHOLLY submerged in the water and
having no sail or other appendage projecting into the air,
which would, of course, introduce other conditions. If,
however, a man were to sit astride of the log and begin to
propel it so that it travels either faster or slower than the