Sách nói: How It Flies or, Conquest of the Air

In these pages, by means of simple language and suitable pictures, the author has told the story of the Ships of the Air. He has explained the laws of their flight; sketched their development to the present day; shown how to build the flying machine and the balloon, and how to operate them; recounted what man has done, and what he hopes to do with their aid. In a word, all the essential facts that enter into the Conquest of the Air have been gathered into orderly form, and are here presented to the public. We who live to-day have witnessed man’s great achievement; we have seen his dream of ages come true. Man has learned to fly! The air which surrounds us, so intangible and so commonplace that it seldom arrests our attention, is in reality a vast, unexplored ocean, fraught with future possibilities. Even now, the pioneers of a 8 countless fleet are hovering above us in the sky, while steadily, surely these wonderful possibilities are unfolded. - Summary by From the Preface