On the occasion of the launching of the first balloon in Italy, a very interesting discussion was raised with regard to raising surfaces in the atmosphere and propelling them downwards — as to whether we experienced the same resistance. Professor Hergesell, of Strasburg, very kindly arranged for some experiments to be carried out. The apparatus was rigged up, and we tried spheres and discs of varying diameters; but with the spheres we were very much bothered, and I may say our chief trouble was with the vertical currents in the tower of the Cathedral. However, the experiments are still going on, and so far we have found that the spheres rise vertically quicker than they descend. It is rather difficult to understand this.

Is the navigable balloon worth improving? That is a question which is frequently asked by the general public. Now there are many of us who, with reason, feel convinced that the ultimate future solution of the problem of aërial navigation will be found to be in the body heavier than air—the aëroplane— and some will doubtless say that it is waste of time to endeavour to improve what appears only capable of improvement within only finite limits, that all our united efforts should be directed to the system which, when certain first principles are successfully applied, will not display those boundary lines to further progress which seem so apparent in the case of navigable balloons.

The title of my paper should really have been “ Stability in Ordinary Conditions of Wind near the Ground,” to indicate that the stability about which I want to talk here to-night is not the equilibrium of a machine in calm air, or in an unfluctuating breeze (if there is such a thing), but the ability which a machine must have to remain stable under ordinary conditions of wind most days in the year. Although my ideas on feathering fans are brought in as one way of meeting the conditions which have certainly up to the present not been provided against in any experiment, I by no means hold by them if any better way could be devised for this vital purpose. Now the ordinary conditions of a breeze near the ground have been ably described by Sir Hiram Maxim and Professor Langley.

I have made many kites subsequently, and of many different forms, but always came back to that represented in the photographs before the meeting. It resembles in some particulars that of Mr. Cody, though I had made it long before I had seen or heard of Mr. Cody's kite. The essential difference is in the wings, where I do away with the eccentric protuberances which he favours. One particular feature I would point out is my employment of steel springs to fly the kite from at the kite-end of the connections. Mr. Cody employs all his springs at the winder end, but I find the double use of springs renders the flight of the kite infinitely more steady.