[Illustration: PLATE I. THE GREAT WHEEL IN ACTION. ] DISCOVERIES AND INVENTIONS OF THE NINETEENTH CENTURY Who saw what ferns and palms were pressed Under the tumbling mountain’s breast, In the safe herbal of the coal? But when the quarried means were piled, All is waste and worthless, till Arrives the wise selecting Will, And, out of slime and chaos, Wit Draws the threads of fair and fit. Then temples rose, and towns, and marts, The shop of toil, the hall of arts; Then flew the sail across the seas To feed the North from tropic trees; The storm-wind wove, the torrent span, Where they were bid the rivers ran; New slaves fulfilled the poet’s dream, Galvanic wire, strong-shouldered steam. EMERSON. DISCOVERIES AND INVENTIONS OF THE NINETEENTH CENTURY BY ROBERT ROUTLEDGE, B.Sc., SOMETIME ASSISTANT EXAMINER IN CHEMISTRY AND IN NATURAL PHILOSOPHY TO THE UNIVERSITY OF LONDON THIRTEENTH EDITION REVISED AND PARTLY RE-WRITTEN, WITH ADDITIONS CONTAINING FOUR HUNDRED AND FIFTY-SIX ILLUSTRATIONS LONDON GEORGE ROUTLEDGE AND SONS, LIMITED BROADWAY, LUDGATE HILL 1900 PREFACE.