A tandem of six or eight six-foot kites exerts a pull of thirty pounds
or more on the main line; but it must not be assumed that such a
tandem would lift and carry through the air a weight of thirty pounds.
The weight of thirty pounds would be carried a short distance; but
as the weight moved off, there would be a sudden lessening of the
resistance on the line, and so of the wind pressure against the kites,
which would soon cause them to sink. A tandem of strong kites in
a good breeze might be made to operate a sort of jumping apparatus
which, after being carried a short distance, would anchor itself to
the ground until the renewed strength of the kites lifted it up again
for another jump. But all kite experts are agreed that a kite's power
for lifting loads clear of the ground must be enormously increased
according as the distance to which the load is to be lifted is
increased. It would be possible, for example, to build a tandem of
kites strong enough to lift a man clear of the ground, supposing him
to be swung in a basket from the main line. This, indeed, has been
actually accomplished. September 18, 1895, in England, Captain
Baden-Powell was lifted to a height of one hundred feet on a
kite-string supported by five large hexagon kites. But Mr. Eddy
calculates that to lift a man of the same weight (one hundred and
fifty pounds) to a height of fifteen hundred feet, with a wind blowing
at the same rate (twenty miles an hour), would require seven kites
with upright and cross-sticks not less than sixty-four feet each in
length.
The only other instance on record where a man has been lifted by a
kite-cord was in the experiment of the great Australian kite expert,
Hargrave, who, on November 12, 1894, placed himself in a sling seat
attached to a tandem of his wonderful box kites, and was swung sixteen
feet clear of the earth. The entire load, including the seat and
appurtenances, amounted to two hundred and eight pounds. Mr. Eddy
calculates that six of his bird-shaped kites, twenty feet in diameter,
would lift a man and basket in safety to a height of one hundred feet,
assuming the wind to be blowing steadily at twenty miles an hour.
[Illustration: PHOTOGRAPHING FROM A KITE-LINE.
NOTE.--In this picture the square box suspended from the upper line is
the camera. The ball hanging from the camera is the burnished signal
which, by its fall, informs the operator on the ground when the
shutter of the camera has opened. The shutter and the ball are
controlled from the ground by the lower line.]