which theology consisted in absurd dogmas and gross superstition, and confused and unintelligible systeme dishonoured the name of philosophy*.

CHAPTER III,

THE SUBJECT CONTINUED.

THE detail of those who, in modern times, have followed mathematical studies with ardour, and united useful discoveries to scientific researches, constitutes the history of some of the greatest efforts of the hu man mind.

Nicholas Copernicus was born at Thorn, a city of Prussia, in 1473. Dissatisfied with the reigning system of Ptolemy, who placed the earth in the centre of the universe, he revived the very ancient opinion which had been taught by Pythagoras nineteen centuries before in the schools of Magna Græcia, He derived his information respecting the astronomical doctrines of the great philosopher of Samos from the, academical questions of Cicero, and the works of Plutarch, as he acknowledged in the dedication of his works to Pope Paul the third. Copernicus maintained that the sun was placed in the centre of the universe, and that Mercury, Venus, the Earth, Mars, Jupiter, and Saturn

* The preceding account of mathematics is very concise and defective. The reader must examine the best mathematical books in the list at the end of this volume.

revolving each upon its axis, move round the sun from west to east. The different revolutions of these six planets are proportioned to their respective distances from the sun, and the circles which they describe cut the ecliptic in different points.* The earth completes its revolution in the space of a year, in a circle which includes the orbit of Venus, and is included by the orbit of Mars. It has another revolution upon its axis in twenty-four hours, and by this movement the distinctions of day and night are produced. The moon, an inferior planet, attendant on the earth, moves round, it in an elliptic orbit, and revolves upon her own axis exactly in the time she goes round the earth. The heavens which form the spacious fields of ether are immoveable, and the stars are fixed in them at an immense distance from the sunt.-Such is the Copernican system, the glory of modern philosophy, and the basis of the subsequent observations of astronomers.

Kepler, born at Weil, in Saxony, in 1571, was the friend of Tycho Brahe, and the associate of his astronomical studies. He has rendered his name illustrious in the annals of science by developing the laws which regulate the motions of the planets. Assisted by the observations of the Danish philosopher, he made the following discoveries. I. That the six primary planets move round the sun not in circles, but in ellipses, having the sun in one of the foci. II. That the planets describe round the sun equal areas in equal times. III. That the squares of the periodical times, in which the planets revolve round the sun, are as the cubes of their mean distances from him. This discovery is

*The planets revolve round the sun in elliptical orbits or paths.

†This is erroneous.

found to be of great use in astronomical calculations, for if the periodical times of two planets be given, and the distance of one of them from the centre; the other may be found by the rule of proportion.

The name of Bacon occurs a second time in the English history connected with the progress and contributing to the honour of science. Sir Francis Bacon, Baron Verulam, early distinguished in the court of Elizabeth by his wit, and afterwards disgraced in that of James the First, by the corruption which he either practised, or allowed, was the great projector of a plan for conducting the researches of philosophy upon the most comprehensive principles. He proposed to substitute experiment for theory, and laid the foundation of the solid and stupendous pyramid of human knowledge, which rises from earth to heaven in due proportion and regular order. Its foundation is the history of the works of nature, its second stage her true principles and various powers; and its summit obscured by clouds, scarcely penetrable by mortal. eye, approaches even to the great Creator himself.

To understand the full meaning of this figurative. allusion, it may be necessary to give some general view of his principal works, viz. his Advancement of Learning-de Augmentis Scientiarum-and Novum Organum.

In his "Advancement of Learning," he has laid down the principles of genuine philosophy, not founded upon hypothesis and conjecture, but truth and experience. His plan required him to take an accurate review of the state of learning. That he might not be bewildered in a subject so complex and extensive, he has arranged the numerous arts according to the three great faculties of the mind-memory, imagination,

and judgment, under three classes-history, poetry, and philosophy. These may be considered as the principal trunks, from which shoot forth all the smaller branches of science. Whatever he found to be imperfect or erroneous, he has pointed out, together with the best means of improvement. At the end of this treatise, he has traced, in one general chart, the several provinces of science that were neglected, or

unknown.

The design of the "Novum Organum," which forms the second and most considerable part of the Advancement of Learning, was to raise and enlarge the powers of the mind by a useful application of reason to all the objects which philosophy considers. Thus does Lord Bacon present to the world a new and superior kind of logic, not intended to supply arguments for controversy, but truths for the use of mankind. It is an art inventive of arts, and productive of real, important, and new acquisitions of knowledge. It commonly rejects the use of syllogism, and sub,. stitutes a severe and genuine induction-an induction which examines scrupulously the subject in question, views it in all possible lights, excludes whatever does not necessarily belong to it, and then draws conclusions as to its real principles and properties. See p. 68, vol. ii. Many proofs may be brought to show how well this mode of inquiry has since succeeded, and how fruitful it has been in new discoveries. The great Newton applied it to the elucidation of the science of optics, and by a variety of experiments has analized the nature and properties of light, the most subtile of all known bodies, with accuracy and precision hardly to have been expected from an examination of subjects the most gross and palpable. The method of induction

has likewise been applied with great success to chemistry, botany, mineralogy, and other branches of science.

In order to preclude objections drawn from the supposed visionary nature, or novelty of his system, Lord Bacon treats in the third part of his instauration, on the "Phænomena Universi”—this is intended to form a collection of materials towards a natural and experimental history. Such a work he thought indispensable, as without it the united endeavours of all mankind, in all ages, would be insufficient to rear, to complete the great structure of the sciences. His "Sylva Sylvarum" is a storehouse of materials, not arranged for ornament, but thrown together for the service of the philosopher, who may select such as suit his purpose, and with them, by the aid of his Novum Organum, build up some part of a self-evident philosophy, which is the crown, and completion of his system. If several eminent men following his steps in the road which he prepared for them, have advanced farther into the provinces of nature and science, and surveyed them with more attention, yet to him is due much of the honour of their discoveries. The fertile genius of Columbus imagined a new world, and he had the boldness to go in search of it, through an unexplored and immense ocean. 'He succeeded in his attempt, and conducted his followers to a spacious, rich and fruitful continent. If succeeding adventurers have penetrated farther into the same regions, and distinguished them with more accuracy, the progress of their discoveries ought to redound as much to his honour, as to their own.

Britain, France, Italy, Germany, and even Russia, have adopted Bacon as their guide in scientific re