They have said there is nothing new under the sun. But then they probably reckoned without such recent discoveries as Rontgen rays, phonographs, and wireless telegraphy, amongst others. Yet, on the other hand, it is very remarkable how people pass by good inventions and good ideas, and won't take to them. Kites, for instance, have been known for hundreds of years. Everyone knows of them all the world over, yet, till a few years ago, no one thought of putting them to any use. When I say no one, I do not mean that exactly, for Franklin and others, of course, used kites for meteorological experiments; Pocock drew a little carriage along with them, and several others suggested their use for lifesaving at sea. But these are the exceptions that prove the rule. They drew attention to the utility of the invention, yet went no further.

Suddenly, and only during the last three or four years, inventors have taken up this longneglected contrivance, land now we hear of new and improved kites being experimented with by many different people in many different countries.

What is without doubt one of the most important attempts to solve the problem of the navigation of the air is now being made on tha shores of the Bodenzee, in Wurtemberg. The general idea is that of what has hitherto been called a dirigible balloon, but this term hardly describes the huge snip with its metal framework and outer cover containing a number of balloons. It is nothing more or less than an aerial steamship.

A paper read at the Society of Arts on Wednesday, Feb. 15, 1899; Captain Baden Powell, Hon. Secretary to the Aeronautical Society of Groat Britain, in the chair.

In the first years of the century, the Russian Academy organised, at St. Petersburg, what may be regarded as the earliest balloon ascent for genuine scientific research. One chief object which they had in view was to determine any difference in conditions existing at various altitudes above plain country as compared with those observed by Humboldt, Saussure, and ethers a t like elevations on mountain heights, and that this is even still an important line of inquiry for which balloons are eminently well suited, I shall hope to make sufficiently clear. The experiments proposed, which, to–day, read quaintly suggestive', were to include an investigation of the power of solar rays, of the existence of electric matter, and of the intensity of the colours of the prism. No results of consequence, however, were obtained.

It has been long known, principally through experiments on soaring, that a large, if not by far the largest, part of the supporting force obtained by birds in regular flight, is probably furnished by upward air pressure on their wings, regarded as planes moving horizontally, with their surfaces slightly inclined to the direction of motion.

Langley's “Experiments on Aero–dynamics” furnish some numerical data for estimating the power required to sustain an aeroplane of given weight, propelled horizontally by a known force, and he applies these to the determination of the problem whether this could be effected by screw propellers, analogous to those of a ship, actuated by machinery of existing type.

A report has been going the rounds of the press abroad to the effect that a party of German aeronauts contemplate making an experimental long–distance balloon trip, starting from Germany and travelling in an easterly direction, the object of the voyage being to discover experimentally how long a balloon may (remain in the air before coming to the ground.

Whether there is any foundation for this report or not, there can be no doubt that experiments of this kind are necessary for the advancement of the science of aeronautics. Long–distance ballooning has been hitherto neglected, as far as practical trials are concerned.

The principle of this invention consists in giving lateral motion to balloons by utilizing the resistance of the air, during successive ascents and descents, by means of a large triangular sail, placed between the bag and the car at an oblique angle with the horizon; and in rotating them at will by means of a smaller rudder–sail, which is capable of turning on a horizontal axis. The sails are constructed to furl readily.

The principle was first applied to a buoy, depressed to the bottom of a running stream. As it rose it could be made to turn in either direction, according to the setting of the rudder, and would proceed in a course opposed to the stream if thus directed, and all by passive means. When weighted it would act similarly during descent. On removal of the weight, it would continue its course whilst re–ascending, and so on. Anyone can experiment for himself, at a trifling cost, in this way.

In the summer of 1898 I constructed a full sized gliding machine with which I made many short flights, ranging from fifty to one hundred feet. This machine was constructed on the plans of the Herring soarer used by Mr. Octave Chanute in his experiments on the borders of Lake Michigan during the summer of 1896, and, although I was not able to make so long a flight as Mr. Herring did, I acquired some knowledge of the management of the apparatus and the difficulties to be overcome. I used the Lilienthal form of curve, which is the arc of a circle, and the height of the curve is 1/12 the length of the chord.

My experiments showed not only that the problem of stability is a very great one, but that it ia very necessary to find some more efficient form of curve than the circle, in order to reduce the power necessary to drive the machine through the air at a sustaining speed. I, therefore, determined to experiment with various surfaces, until I found one offering much less resistance than the one I was using.

How birds fly, and what is the force employed to sustain and propel them, has been so often discussed that most would think the subject exhaustively explained and thoroughly understood. Yet it is doubtful whether such is the case, seeing that many now are inclined to ascribe the phenonemena of forward flight to the curvature of the surface of the wing. Another view, and a nearly opposite one, is this, that the wing's chief function is that of sustaining, and has but slight propelling property, and what propelling power the curvature of the under surface endows the wing with, is exerted in giving a forward course to the wing itself in its descent; this is the view that will be sought to be worked out in this paper.