BACON. Were it possible to traco the services which were rendered to industry, through the medium of science, by Roger Bacon in the 13th century, and by Francis Bacon in the 16th and 17th, the list would doubtless be an important one ; but it would belong to the biography of Science rather than of Art. The Opus Majus of Roger Bacon laid the groundwork for better reason ing in later ages ; but the great points by which Bacon is known are his reputed know ledge of gunpowder and of the telescope. With regard to the former, it is not at all clear that what we call gunpowder is intended, though some detonating mixture, of which saltpetre is an ingedient, is spoken of as commonly known. In respect to the teles cope, it must be admitted that Bacon had conceived the instrument, though there is no proof that he carried his conception into practice, or invented it. The question has been agitated whether the invention of spec tacles is due to Bacon, or whether they had been introduced just before he wrote. He
certainly describes them, and explains why a plane convex glass magnifies. But he seems to us to speak of them as already in use.
In respect to the far greater Francis Bacon familiarly known as Lord Bacon, the contri butions to Art or Industry were more indiract ; for his scientific kbotirs applied chiefly to the logic of science, to the best means by which the human mind may master the difficulties which lie at the threshold of all scientific enquiries. He was in fact re moved two stages from the philosophy of manufactures : he taught the man of science how to grasp theoretical principles ; and the man of science, thus taught, wa.1 in a con dition to apply his science to the practical wants of the manufacturer, the mechanist, and the engineer.