第82章 CHAPTER XXIII. NEW DEPARTURES IN AEROSTATION.(4)

Distinct from, and supplementing, the records obtained by free balloons, manned or unmanned, are those to be gathered from an aerostat moored to earth. It is here that the captive balloon has done good service to meteorology, as we have shown, but still more so has the high-flying kite. It must long have been recognised that instruments placed on or near the ground are insufficient for meteorological purposes, and, as far back as 1749, we find Dr. Wilson, of Glasgow, employing kites to determine the upper currents, and to carry thermometers into higher strata of the air. Franklin's kite and its application is matter of history. Many since that period made experiments more or less in earnest to obtain atmospheric observations by means of kites, but probably the first in England, at least to obtain satisfactory results, was Mr. Douglas Archibald, who, during the eighties, was successful in obtaining valuable wind measurements, as also other results, including aerial photographs, at varying altitudes up to 1,000 or 1,200 feet.

From that period the records of serious and systematic kite flying must be sought in America. Mr. W. A. Eddy was one of the pioneers, and a very serviceable tailless kite, in which the cross-bar is bowed away from the wind, is his invention, and has been much in use. Mr. Eddy established his kite at Blue Hill--the now famous kite observatory--and succeeded in lifting self-recording meteorological instruments to considerable heights. The superiority of readings thus obtained is obvious from the fact that fresh air-streams are constantly playing on the instruments.

A year or two later a totally dissimilar kite was introduced by Mr. Lawrence Hargrave, of Sydney, Australia. This invention, which has proved of the greatest utility and efficiency, would, from its appearance, upset all conventional ideas of what a kite should be, resembling in its simplest form a mere box, minus the back and front. Nevertheless, these kites, in their present form, have carried instruments to heights of upwards of two miles, the restraining line being fine steel piano wire.

But another and most efficient kite, admirably adapted for many most important purposes, is that invented by Major Baden-Powell. The main objects originally aimed at in the construction of this kite related to military operations, such as signalling, photography, and the raising of a man to an elevation for observational purposes. In the opinion of the inventor, who is a practiced aeronaut, a wind of over thirty miles an hour renders a captive balloon useless, while a kite under such conditions should be capable of taking its place in the field. Describing his early experiments, Major, then Captain, Baden-Powell, stated that in 1894, after a number of failures, he succeeded with a hexagonal structure of cambric, stretched on a bamboo framework 36 feet high, in lifting a man--not far, but far enough to prove that his theories were right. Later on, substituting a number of small kites for one big one, he was, on several occasions, raised to a height of 100 feet, and had sent up sand bags, weighing 9 stone, to 300 feet, at which height they remained suspended nearly a whole day.

This form of kite, which has been further developed, has been used in the South African campaign in connection with wireless telegraphy for the taking of photographs at great heights, notably at Modder River, and for other purposes.

It has been claimed that the first well-authenticated occasion of a man being raised by a kite was when at Pirbright Camp a Baden-Powell kite, 30 feet high, flown by two lines, from which a basket was suspended, took a man up to a height of 10 feet.

It is only fair, however, to state that it is related that more than fifty years ago a lady was lifted some hundred feet by a great kite constructed by one George Pocock, whose machine was designed for an observatory in war, and also for drawing carriages along highways.