e other valves being closed. The current
rushing through these impinged on the earth with such force as to
drive the boat upwards, while the air itself continued to supply the
necessary fulcrum. When a sufficient elevation was reached the
flexible tube at that end of the vessel which pointed away from the
desired destination, was brought into action, while by the partial
closing of the valves the current rushing through the eight vertical
tubes was reduced to the small amount required to maintain the
elevation reached. The great volume of the current, being now directed
through the large tube pointing downwards from the stern at an angle
of about forty-five degrees, while helping to maintain the elevation,
provided also the great motive power to propel the vessel through the
air. The steering was accomplished by the discharge of the current
through this tube, for the slightest change in its direction at once
caused an alteration in the vessel's course. But constant supervision
was not required. When a long journey had to be taken the tube could
be fixed so as to need no handling till the destination was almost
reached. The maximum speed attained was about one hundred miles an
hour, the course of flight never being a straight line, but always in
the form of long waves, now approaching and now receding from the
earth. The elevation at which the vessels travelled was only a few
hundred feet--indeed, when high mountains lay in the line of their
track it was necessary to change their course and go round them--the
more rarefied air no longer supplying the necessary fulcrum. Hills of
about one thousand feet were the highest they could cross. The means
by which the vessel was brought to a stop on reaching its
destination--and this could be done equally well in mid-air--was to
give escape to some of the current force through the tube at that end
of the boat which pointed towards its destination, and the current
impinging on the land or air in front, acted as a drag, while the
propelling force behind was gradually reduced by the closing of the
valve. The reason has still to be given for the existence of the eight
tubes pointing upwards from the bulwarks. This had more specially to
do with the aerial warfare. Having so powerful a force at their
disposal, the warships naturally directed the current against each
other. Now this was apt to destroy the equilibrium of the ship so
struck and to turn it upside down--a situation sure to be