Progress of Science in the Eighth Epoch

The march of the sciences is rapid and brilliant. The Algebraic language becomes generalized, simplified and perfected, or rather it is now only that it was truly formed. The first foundations of the general theory of equations are laid, the nature of the solutions which they give is ascertained, and those of the third and fourth degree are resolved.

The ingenious invention of logarithms, as abridging the operations of arithmetic, facilitates the application of calculation to the various objects of nature and art, and thus extends the sphere of all those sciences in which a numerical process is one of the means of comparing the results of an hypothesis or theory with the actual phenomena, and thus arriving at a distinct knowledge of the laws of nature. In mathematics, in particular, the mere length and complication of the numerical process practically considered, bring us, upon certain occasions, to a term beyond which neither time, opportunity, nor even the stretch of our faculties, can carry us; this term, had it not been for the happy intervention of logarithms, would have also been the term beyond which science could never pass, or the efforts of the proudest genius proceed.

The law of the descent of bodies was discovered by Galileo, from which he had the ingenuity to deduce the theory of motion uniformly accelerated, and to calculate the curve described by a body impelled into the air with a given velocity, and animated by a force constantly acting upon it in parallel directions.

Copernicus revived the true system of the world, so long buried in oblivion, destroyed, by the theory of apparent motions, what the senses had found so much difficulty in reconciling, and opposed the extreme simplicity of the real motions resulting from this system, to the complication, bordering upon absurdity, of the Ptolemean hypothesis. The motions of the planets were better understood; and by the genius of Kepler were discovered the forms of their orbits, and the eternal laws by which those orbits perform their evolutions.

Galileo, applying to astronomy the recent discovery of telescopes, which he carried to greater perfection, opened to the view of mankind a new firmament. The spots which he observed on the disk of the sun led him to the knowledge of its rotation, of which he ascertained the precise period, and the laws by which it was performed. He demonstrated the phases of Venus, and discovered the four satellites that sarround and accompany Jupiter in his immense orbit.

He also furnished an accurate mode of measuring time, by the vibrations of a pendulum.

Thus man owes to Galileo the first mathematical theory of a motion that is not at once uniform and rectilinear, as well as one of the mechanical laws of nature; while to Kepler he is indebted for the acquisition of one of those empirical laws, the discovery of which has the double advantage of leading to the knowledge of the mechanical law of which they express the result, and of supplying such degrees of this knowledge as man finds himself yet incapable of attaining.

The discovery of the weight of the air, and of the circulation of the blood, distinguish the progress of experimental philosophy, born in the school of Galileo, and of anatomy, already too far advanced not to form a science distinct from that of medicine.

Natural history, and chymistry, in spite of its chimerical hopes and its enigmatical language, as well as medicine and surgery, astonish us by the rapidity of their progress, though we are frequently mortified at the sight of the monstrous prejudices which these sciences still retain.

Without mentioning the works of Gesner and Agricola containing such a fund of real information, with so slight a mixture of scientific or popular errors, we observe Bernard de Palissi sometimes displaying to us the quarries from which we derive the materials of our edifices; sometimes masses of stone that compose our mountains formed from the skeletons of sea animals, and authentic monuments of the ancient revolutions of the globe; and sometimes explaining how the waters, raised from the sea by evaporation, restored to the earth by rain, stopped by beds of clay, assembled in snow upon the hills, supply the eternal streams of rivers, brooks, and fountains: while John Rei discovered those combinations of air with metallic substances, which gave birth to the brilliant theories by which, within a few years, the bounds of chymistry have been so much extended.

After the invention of the printing press, the sciences flourish in many fields.