ELEMENTARY TREATISE ON NATURAL PHILOSOPHY. BY A. PRIVAT DESCHANEL, FORMERLY PROFESSOR OF PHYSICS IN THE LYCÉE LOUIS-LE-GRAND, INSPECTOR OF THE ACADEMY OF PARIS. TRANSLATED AND EDITED, WITH EXTENSIVE MODIFICATIONS, BY J. D. EVERETT, M.A., D.C.L., F.R.S., F.R.S.E., PROFESSOR OF NATURAL PHILOSOPHY IN THE Part I.-MECHANICS, HYDROSTATICS, AND PNEUMATICS. ILLUSTRATED BY 180 ENGRAVINGS ON WOOD, AND ONE COLOURED PLATE. BLACKIE & SON, OLD BAILEY, E. C.; GLASGOW, EDINBURGH, AND DUBLIN. 1880. All Rights Reserved. PREFACE TO THE FIRST EDITION. I DID not consent to undertake the labour of translating and editing the “TRAITÉ ÉLÉMENTAIRE DE PHYSIQUE" of Professor Deschanel until a careful examination had convinced me that it was better adapted to the requirements of my own class of Experimental Physics than any other work with which I was acquainted; and in executing the translation I have steadily kept this use in view, believing that I was thus adopting the surest means of meeting the wants of teachers generally. The treatise of Professor Deschanel is remarkable for the vigour of its style, which specially commends it as a book for private reading. But its leading excellence, as compared with the best works at present in use, is the thoroughly rational character of the information which it presents. There is great danger in the present day lest science-teaching should degenerate into the accumulation of disconnected facts and unexplained formula, which burden the memory without cultivating the understanding. Professor Deschanel has been eminently successful in exhibiting facts in their mutual connection; and his applications of algebra are always judicious. The peculiarly vigorous and idiomatic style of the original would be altogether unpresentable in English; and I have not hesitated in numerous instances to sacrifice exactness of translation to effective rendering, my object being to make the book as useful as possible to English readers. For the same reason I have not scrupled to suppress or modify any statement, whether historical or philosophical, which I deemed erroneous or defective. In some instances I have endeavoured to simplify the reasonings by which propositions are established or formulæ deduced. As regards weights and measures, rough statements of quantity have generally been expressed in British units; but in many cases the numerical values given in the original, and belonging to the metrical system, have been retained, with or without their English |