Page:Popular Science Monthly Volume 53.djvu/64

52 largely social. A recent announcement comes as a surprise to everybody, that the, Japanese records prove that six hundred years ago kites were used by this people in war time for carrying up observers to detect the position of an enemy's forces.

After all, America must be credited with the first application of the kite to scientific investigation; Ben Franklin—as all intelligent persons know—being the experimenter from whose discoveries large results in electrical science have proceeded. Numerous experiments in this direction followed his initiative, in France and, with less fervor, in England; while in Russia a zealous scientist lost his life by his temerity with a metallically equipped kite in a thunderstorm.

Perhaps this catastrophe was the cause of the abandonment of this method of investigation of the upper atmosphere, for nothing that attracted much attention was again accomplished by kites until the year 1894, when the Blue Hill investigations began.

The first year's work at this observatory (a private institution, established and sustained by Mr. A. Lawrence Botch, from public spirit) made little addition to the knowledge previously acquired by amateur fliers; but the succeeding years show marked advances.

At present it is usual, in flying flat kites, to send up several on the same main line. Generally a small kite is first sent up, and, when this is securely mounted, a larger one, attached to the main line perhaps a hundred feet below by about that length of its own string, is started after its leader.

As the number of kites in the tandem increased, more strength was required at the lower end of the line to withstand the pull; so the reel quickly became an important part of the apparatus. The labor of winding was such that the reel was provided with a crank, and mounted more and more strongly, and a recording wheel and dial were soon added to measure the line as it ran out. The apparatus was then made portable by combining it with a sort of wheelbarrow.

Not only the number of kites but the height of their ascent increased the strain on the wheel, and one after another—though of solid oak-—were crushed by the drawing of the concentric layers in winding in, especially after the change was made to a metal string.

Last season (1897) a unique reel was introduced in which a two-horse power steam engine took the place of human muscle for winding in. Steam is supplied by a boiler heated by oil spray as fuel, these and the reel proper being mounted on the same portable base. Included in the winding apparatus is a strain-wheel around which the wire passes four or five times, running from this to the drum of the storage reel—on which it is wound lightly and evenly by automatic action. The wire comes in from and goes out to the