Will the same progress which, in our own times especially, has been of such vast dimensions, and manifested itself in so many directions, continue to be progressive? And if so--for who could think of reaction, since the art of printing has guarded against any furrow of the human mind being ever effaced--where is to be the ultimate goal of the progress of our successors? Where are we to look for the fruits of those innumerable germs which the present generation is sowing for the benefit of those that will come after them? These, and similar other questions, occupied my mind when, seated one afternoon in my comfortable arm-chair, I allowed my thoughts freely to wander amid the manes of those that preceded us. I thought of our own Musschenbroek, Gravesande, Huyghens, and Stevin, and of what would be their surprise were they to reappear on this earth, and gaze upon the marvellous works of modern machinery; I passed in review a Newton and Galileo, with so many others, founders of an edifice which they themselves would not now recognise. I thought of steam engines and electric telegraphs, of railways and steamboats, of mountain tunnels and suspension bridges, of photography and gasworks, of the amazing strides lately made by chemistry, of telescopes and microscopes, of diving bells and aëronautics; aye, and of a hundred other things, which, in motley array, wildly crossed my mind, though all corresponding in this that they loudly proclaimed the vast and enormous difference between the present and the past. The line of demarcation between the one and the other revealed itself still more clearly to me as my thoughts carried me further back into the past and the ghost of Roger Bacon seemed to rise before my imagination. This thirteenth-century child was a scholar who surpassed all his contemporaries in sound judgment and knowledge of natural science; alas! his fate was the ordinary one in store for all those whose light shone above that of others in those darkest of ages. He was accused of witchcraft, and cast into a dungeon, there doomed to sigh for ten weary years, after which, as the rumour goes, he died in his prison. The memory of that illustrious man called to my mind some passages of his writings, from which it will be seen how he, as if endowed with the seer's gift, did actually foretell, some six hundred years ago, that which since, and chiefly in our own time, has become an array of realities. For example: "It is possible," says he, "to construct spying-glasses by which the most distant objects can be drawn near to us, so that we shall be able to read the most minute writing at an almost incredible distance, to see all kinds of diminutive objects, and to make the stars appear wherever we choose." "We might make waggons that could move along with great velocity, and without being drawn by animals." "Similar other machines might be had, as, for example, bridges without pillars or supports of any kind."