LVII THE DEVELOPMENT OF MATERIAL KNOWLEDGE

achievement. A successful flying machine—but not a machine large enough to take up a human body—was made by Professor Langley of the Smithsonian Institute of Washington as early as 1897. By 1909 the aeroplane was available for human locomotion. There had seemed to be a pause in the increase of human speed with the perfection of railways and automobile road traction, but with the flying machine came fresh reductions in the effective distance between one point of the earth’s surface and another. In the eighteenth century the distance from London to Edinburgh was an eight days’ journey; in 1918 the British Civil Air Transport Commission reported that the journey from London to Melbourne, halfway round the earth, would probably