Plumb line, a. 202 Pneumatic trough, c. 125 Poikilite, c. 530 Polar decompositions, c. 158 Polarization, b. 375, 403, 415, 535 circular, b. 388, 444 elliptical, b. 447 movable, b. 425 plane, b. 444 of heat, b. 463 Poles (voltaic), c. 165 of maximum cold, b. 480 Potential levers, b. 122 Power and act, a. 56 Precession of the equinoxes, a. 186 Predicables, a. 272 Predicaments, a. 272 Preludes of epochs, a. 12 Primary rocks, c. 503 Primitive rocks, c. 503 a. 431 Philolaic, a. 434 Carolinian, a. 434 Terminology, c. 307 Theory of analogues, c. 457 Thick plates, colours of, b. 383 Three principles (in Chemistry), c. 106 Toletan tables, a. 225 Transition rocks, c. 530 "A JUST story of learning, containing the antiquities and originals of KNOWLEDGES, and their sects; their inventions, their traditions, their diverse administrations and managings; their flourishings, their oppositions, decays, depressions, oblivions, removes; with the causes and occasions of them, and all other events concerning learning, throughout all ages of the world; I may truly affirm to be wanting. "The use and end of which work I do not so much design for curiosity, or satisfaction of those that are the lovers of learning: but chiefly for a more serious and grave purpose; which is this, in few words, that it will make learned men more wise in the use and administration of learning." BACON, Advancement of Learning, book ii. 1 INTRODUCTION. It is my purpose to write the history of some of the most important of the physical sciences, from the earliest to the most recent periods. I shall thus have to trace some of the most remarkable branches of human knowledge, from their first germ to their growth into a vast and varied assemblage of undisputed truths; from the acute, but fruitless, essays of the early Greek philosophy, to the comprehensive systems, and demonstrated generalizations, which compose such sciences as the Mechanics, Astronomy, and Chemistry, of modern times. The completeness of historical view which belongs to such a design, consists, not in accumulating all the details of the cultivation of each science, but in marking clearly the larger features of its formation. The historian must endeavour to point out how each of the important advances was made, by which the sciences have reached their present position; and when and by whom each of the valuable truths was obtained, of which the aggregate now constitutes a costly treasure. |