Development in size and speed depend on future experimenting, and flights have already been made both in France and Russia by giant aeroplanes, in which, in one case nine, and in the other fifteen passengers, exclusive of the pilot were carried at one time; while the later Zeppelins are capable of lifting to a height of over 12,000 feet, a crew of thirty odd, with a further weight of bombs and war material aboard, and flying distances of over 800 miles. Again, there are the orthropic and the ornithropic types of craft, which their inventors claim to be capable of rising vertically from the ground to a height of 10,000 feet. Combining these principles we ought within the space of ten years to be in possession of aircraft capable of flying at over 150 miles an hour, with a cargo of many hundred tons aboard, and with a radius of over 3,000 miles, able to start and land with ease in a confined space about the size of Leicester Square. The aerial landing grounds will be the flat roofs of gigantic buildings specially constructed in the center of London. Automatic lifts will convey the passengers from the air level to the street level, where they will be deposited in electric trains, running in all directions. Impracticable, say the critics, but so they said when Count Zeppelin and the Wrights first started their experiments. PROPERTIES OF WAR AND PEACE MACHINES There is not, and there never was, on this earth a new idea so well deserving of examination as the science of Aeronautics. The history of that science deals with the most momentous invention in the history of civilization. No other science allures the imagination so far forward into the dim future, when the business of the world will be carried up from the level of the sea and the land to that of mid-air, and when travel will be so rapid and safe that space will almost cease to be an obstacle to man’s communications.