PHYSICAL AND MATHEMATICAL SCIENCES. Ill

very carefully recorded, and to trace their beginning isoften like attempting to pursue a river to its source,where we are soon totally baffled among the multipli-city of small streams which unite to form it.

Dr. Smith, after fully discussing all the evidence, isof opinion that lenses were in use for assisting visionabout 1313, but that nothing further can be collectedwith certainty. Some passages in Bacon ’s writings,which were once interpreted as referring to the princi-ple of the telescope, seem to have been completely mis-understood, and to contain in reality nothing of thekind. He seems unquestionably to have believed in thepossibility of transmuting metals, and probably also inastrology ; but was superior to his age in absolutely re-jecting the pretensions of magic.

Roger Bacon ’s great merit is to be found, not somuch in the mere details of his various inventions andprojects, as in the bold appeal which he made toexperiment and the observation of nature ; he stoodforth as the champion of unfettered enquiry, and vindi-cated the rejection of all the trammels of authority inmatters of science. In an age like that in which helived, indeed, there were few capable of profiting by hisexample and instructions ; but there were not wantingthose who were able to appreciate their value, noragain those who had good reason to dread the influenceof such principles, and who accordingly took measuresto impede their progress, and, if possible, to suppresstheir promulgation. A pretext was supplied in the alle-gation that Bacon ’s pursuits were allied to magic,though he had actually written a work expressly againstthat art ; he was accordingly prohibited from readinglectures in the university, and was subjected to con-finement in his convent. He had his eyes open to thecorruptions and superstitions of the Romish church,and avowed the most enlightened views in recom-mending the cultivation of natural science, with theexpress object of leading men to more just concep-tions of the true foundations of religion: this, of course,