The subject on which I propose to address you to-night is certainly one with which this generation is not only rightly challenged, but one with which one could almost say that it should be taunted. For nowadays we pride ourselves on the fact that no great invention can be universally acknowledged to be successful without its being very rapidly turned to the economic service of mankind. But aviation has been a human accomplishment for more than half a generation, and so far no aeroplane has earned its cost and keep.

In the old days, when manufactures were primitive, when accurate machine tools did not exist, when very few people were interested or instructed in scientific things and no means existed for instructing or interesting the many, it was natural enough that great inventions should have been made and then allowed to expire, so to speak, without being used.