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.]