But, as a means of amusement, the idea of aërial travel has great promise. Small one-man flying-machines, or the aërial counterpart of tandem bicycles, will no doubt be common enough. We shall fly for pleasure; and just as thousands of working men and women now take a Saturday-afternoon spin on a bicycle, so they will go for a sky-trip, and visit interesting mountain-tops for (non-alcoholic) picnics. The bicycle or the motor-cycle will perhaps be the point of development. It is quite certain that within the next ten or fifteen years some means will have been discovered by which we can ride on a single wheel. The saving of weight thus effected will go a long way towards surmounting the flight problem. Then, when motor-unicycles are presently propelled by force transmitted (in the same way as Marconi's telegrams) from a fixed power-house, the difficulty of flight will be within sight of an easy solution. Any competent mechanician of the present day could design a flying-machine if the mere weight of the motive appliance could be overcome. When the motor is fixed on terra firma, and the vehicle only needs to carry a device for utilising the ætheric waves which the source of power wirelessly transmits, flight will be at least as simple a matter as wireless telegraphy is to-day. When it is possible to cross the Atlantic in a day by means of surface-riding ships, propelled, like the flying-machines, by ætheric force, the field of amusement will be vastly increased, and although (as I shall show) it will no longer be necessary to travel in order to "see the sights" of any part of the world, the pleasure of being present at the actual events of life in different countries will probably never pall. So long as any parts of the world remain comparatively unfamiliar, young men and maidens will love travel. When it is possible, wrapped in warm woollens and provided with portable heating-appliances, to pay a short visit to the Arctic circle and enjoy the matchless spectacle of the Aurora Borealis amid the awe-compelling obscurities of the Polar night: when, with even less inconvenience, we can take a trip to the tropics and witness, here the unchangeable processes of Nature's luxuriance, there the perhaps immutable conservatism of the East, the new leisure of the coming time will have great stores of recreation for those happy enough to live in the dawning twenty-first century.