relative to immaterial points, which impose only needless labor and uncertainty upon the student. Above all things, I have sought to write a straight, plain, simple, and, I hope, fairly logical and interesting story. I have rigidly excluded technicalities and scientific demonstrations, which, however interesting to the professional electrician, are as Greek to the general reader; for I address this no more to the wise men of the wires and the dynamos and the batteries, than to the great public whom we all serve, and for whose good we all labor. Popular science, so called, is too often dilute science. Scientific discussions of a didactic or abstract nature, or involving a Babylonish terminology, and requiring minds trained to understand them, cannot be rendered any easier to the mental digestion of intellects engrossed in other departments of the world's work, and, hence, not so educated, by mechanically mixing them with the water of an engaging rhetoric. The facts and the arguments based on them must be digested and brought into true solution, so that the food offered will be easily assimilable; and that is what I have tried here to do. Perhaps this work may usefully tend to show that electricity, at the present time, is not "in its infancy." It has undoubtedly a vast amount of work yet to do, and—I am patriotic enough to believe at the hands of our American inventors, first of all-will yet accomplish things undreamt of in our philosophy; but it will do this not with the feeble uncertainty of the nursling, but with the vigor and might of maturity. Moreover, although in ancient days electricity, in common with all other natural manifestations, was regarded as a mystery, none the less the knowledge of it, as these pages seek to prove, forced its way through the clouds of ignorance and superstition with the unerring directness of a projectile driven through the mist from a modern gun. Electricity is not now occult, it is not mystic, it is not magic, its workings are no more wonderful than are the rise and fall of the tides; in fact, it may be safely said, that we know more about its laws and their consequences than we do about those which determine the fall of a stone to the ground. I end this essay-which has been more of pleasure than of toil-fully conscious of the errors and inconsistencies which must be in it. At every turn there have been tangled skeins to unravel, whereof the true clews have, no doubt, often been missed; diverging roads, where one selects a path never without misgivings. But with all due submission, I venture to believe that a faithful effort, even if misdirected, is better than none at all, although in that consciousness may well lie the only justification for this book. PARK BENJAMIN. Greek knowledge of the lodestone and the Samothracian rings. 22 Theophrastus, and the first physical description of the amber effect . The University of Alexandria. Legends of magnetic suspension-Mahomet's coffin. Lucretius' De Natura Rerum and its description of magnetic effects . CONTENTS. The Chinese not natural navigators Nor reliable astronomers. Nor competent inventors. The Mariner's Compass probably not of Chinese origin. The Dark Ages and the rise of Scholasticism. . First distinction between magnetic and electric effects drawn by St. The punishment for tampering with the Compass . The Compass possibly of Finn origin and emanating from Wisbuy. 145 And other mediæval poems referring to magnetic polarity The spurious treatise of Aristotle. Attempts to account for Compass variation by the Magnetic Rocks. The voyages of Vasco da Gama and Magellan . |