The following is a statement of the results of certain acoustical investigations, in conducting which the late author was favoured by somewhat exceptional facilities. He writes: “ In a long series of endeavours, during balloon travel, to aid in the investigation of the physical constitution of the upper air, I have constantly sought to determine variations, however trivial or transient, in the currents through which the balloon has had to climb. Results have been alike curious and instructive. Thus, a globe of thistle down will not sport in the air as it does above the hedge rows, but will take an independent course, often at variance with that of the balloon, striking off widely in an apparently chance direction, or, more curiously, mounting upwards past the balloon, even though this may be also ascending from discharge of ballast.

This machine, called by its inventor the Aëromobile, is designed, to accomplish gliding flight by the aid of propellers, to carry one man, and to manœuvre on or near the ground, before free flight is attempted, in order that its practicability may be thoroughly tested.

Theoretically, the fundamental principle upon which the practicability of the invention is based, is the determination by experiment of the exact relation existing between speed, supporting area, and weight, in order that, any two of the three being constant, the other may be varied in such a way that the result in a machine of this description shall always be equilibrium.