The modern system of flying kites tandem was devised by Mr. Eddy in
1890, although it was hit upon two years later independently by Dr.
Alexander B. Johnson, the distinguished surgeon of the Roosevelt
Hospital in New York. The tandem system makes it possible to send
kites to far greater altitudes than had ever been previously attained.
And here the best record is undoubtedly held by one of Mr. Eddy's
tandems, sent aloft at Bayonne, on November 7, 1893. Mr. Eddy began to
send up the kites at 7:30 A.M.; but, being hampered by light breezes
from the east, found he was kept busy until half-past three in the
afternoon in getting nine kites aloft. He had paid out nearly two
miles of cord, when the top kite, a little two-footer, stood straight
over the spar buoy in Newark Bay. The lowest kite, a six-footer, was
hovering some distance inland from the shore, on a line from the shore
to Mr. Eddy's house (where the end of the line was anchored) measuring
fifty-five hundred feet by the surveyor's map. Taking two observations
from the two ends of this base line, Mr. Eddy's kite-quadrant showed
angles of thirty-five and sixty-six degrees; and these data, by simple
methods of triangulation, were sufficient to determine the altitude
of the kite, which was found to be five thousand five hundred and
ninety-five feet--or something over one mile. The kites were seen by
hundreds of persons during the fifteen hours that they remained up,
the experiment coming to an abrupt end at ten o'clock that night by
the blowing away of the two upper kites in the increasing wind. The
escaped kites disappeared in Newark Bay, along with three thousand
feet of the line.
[Illustration: KITE-DRAWN BUOY.
Invented by Prof. J. Woodbridge Davis. This buoy lacks the steering
appliances of the one shown below, and travels simply in a line with
the kite that draws it.]
Much interest attaches from a scientific point of view to experiments
designed to test how great an altitude may be reached by kites; and
for a year past Mr. Eddy has been working in this direction for
the Smithsonian Institution, the hope being that he will ultimately
succeed in sending kites two miles above the earth's surface.
Professor Langley has been following these experiments with great
interest, and has furnished Mr. Eddy with a special quality of silk
cord which, it is believed, will give better results in meteorological
observation than the ordinary hempen twine or rope. The great
difficulty that Mr. Eddy finds in the way of making his kites reach
great altitudes, is the pull on the cord, which increases greatly
as the kites rise higher. It is probable that a tandem of fifteen or
twenty big kites, reaching to a mile above the earth's surface, would
exert a pull of one hundred pounds; while at a height of two miles
they might, Mr. Eddy thinks, exert a pull of three hundred and fifty
pounds; and at a height of three miles, a pull of seven hundred
pounds. However great the pull, it is essential to successful flying
that the man in control be able to let out or reel in the main line
with great rapidity, and it is evident that a dozen men could not by
hand alone accomplish this if the kites were sent as high as might
be. It is likely, therefore, that, as the importance of scientific
kite-flying becomes more widely understood, some simple dummy engine
will be devised for rapidly turning the windlass on which the main
line is wound.
Mr. Eddy has made frequent experiments with rain-kites, which he used
for the first time in November, 1893. It is true that Franklin sent
up a flyer during a shower, but in his case the rain was merely an
accident accompanying the electric storm, which was his only concern.
Mr. Eddy, however, has sent up kites in the rain for the purpose of
studying cloud altitudes and other meteorological phenomena; and by
this means he has discovered what was not previously believed to be
true: that clouds sometimes sink to within six hundred feet of the
earth's surface without actually coming down to it. In fact, Mr. Eddy
has had kites disappear in a cloud at a height of only five hundred
and sixty-eight feet. It has sometimes happened that clouds settling
toward the earth have obscured the kites gradually, the top one
becoming invisible first, and then the others in succession. Mr. Eddy
has found that by such indications he is able to foretell the approach
of fog four or five hours before it reaches the earth's surface, so
slowly do the clouds settle through the air strata.
[Illustration: DIRIGIBLE KITE-DRAWN BUOY.
This is the buoy invented by Prof. J. Woodbridge Davis for conveying
messages, food, or life-lines between disabled vessels and the shore.
The buoy is drawn over the water by the kite-line, like the one shown
above, but the setting of the keel and the three guy-ropes give it
whatever direction is desired.]
[Illustration: THE KITE-BUOY IN SERVICE.]
It is best to make rain-kites of oil-skin or paraffine paper, as the
ordinary paper or cloth becomes saturated with the dampness and very
heavy, thus lessening the buoyancy of the line. So penetrating is the
dampness of clouds, even without a rain-storm, that the wooden frames
sometimes become warped and the paste seams soak open.