raised the money he needed it was by pawning their goods in the hope of repayment from Clement. Nor was this all; the work itself, abstruse and scientific as was its subject, had to be treated in a clear and popular form to gain the Papal ear. But difficulties which would have crushed another man only roused Roger Bacon to an almost superhuman energy. By the close of 1267 the work was done. The "greater work," itself in modern form a closely-printed folio, with its successive summaries and appendices in the "lesser" and the "third" works (which make a good octavo more), were produced and forwarded to the Pope within fifteen months. [Sidenote: The Opus Majus] No trace of this fiery haste remains in the book itself. The "Opus Majus" is alike wonderful in plan and detail. Bacon's main purpose, in the words of Dr. Whewell, is "to urge the necessity of a reform in the mode of philosophizing, to set forth the reasons why knowledge had not made a greater progress, to draw back attention to sources of knowledge which had been unwisely neglected, to discover other sources which were yet wholly unknown, and to animate men to the undertaking by a prospect of the vast advantages which it offered." The developement of his scheme is on the largest scale; he gathers together the whole knowledge of his time on every branch of science which it possessed, and as he passes them in review he suggests improvements in nearly all. His labours, both here and in his after works, in the field of grammar and philology, his perseverance in insisting on the necessity of correct texts, of an accurate knowledge of languages, of an exact interpretation, are hardly less remarkable than his scientific investigations. From grammar he passes to mathematics, from mathematics to experimental philosophy. Under the name of mathematics indeed was included all the physical science of the time. "The neglect of it for nearly thirty or forty years," pleads Bacon passionately, "hath nearly destroyed the entire studies of Latin Christendom. For he who knows not mathematics cannot know any other sciences; and what is more, he cannot discover his own ignorance or find its proper remedies." Geography, chronology, arithmetic, music, are brought into something of scientific form, and like rapid sketches are given of the question of climate, hydrography, geography, and astrology. The subject of optics, his own especial study, is treated with greater fulness; he enters into the question of the anatomy of the eye besides discussing problems which lie more strictly within the province of optical science. In a word, the "Greater Work," to borrow the phrase of Dr. Whewell, is "at once the Encyclopedia and the Novum Organum of the thirteenth century." The whole of the after-works of Roger Bacon--and treatise after treatise has of late been disentombed from our libraries--are but developements in detail of the magnificent conception he laid before Clement. Such a work was its own great reward.