"There are to be found in his writings new and ingenious views of Optics,--as, on the refraction of light, on the apparent magnitude of objects, on the magnified appearance of the sun and moon when on the horizon. He describes very exactly the nature and effects of concave and convex lenses, and speaks of their application to the purposes of reading and of viewing distant objects, both terrestrial and celestial; and it is easy to prove from his writings that he was either the inventor or the improver of the telescope. He also gives descriptions of the camera obscura and of the burning-glass. He made, too, several chemical discoveries. In one place he speaks of an inextinguishable fire, which was probably a kind of phosphorus. In another he says that an artificial fire could be prepared with saltpetre and other ingredients which would burn at the greatest distance, and by means of which thunder and lightning could be imitated. He says that a portion of this mixture of the size of an inch, properly prepared, would destroy a whole army, and even a city, with a tremendous explosion accompanied by a brilliant light. In another place he says distinctly that thunder and lightning could be imitated by means of saltpetre, sulphur, and charcoal. As these are the ingredients of gunpowder, it is clear that he had an adequate idea of its composition and its power. He was intimately acquainted with geography and astronomy. He had discovered the errors of the calendar and their causes, and in his proposals for correcting them he approached very nearly to the truth. He made a corrected calendar, of which there is a copy in the Bodleian Library in Oxford. In moral philosophy, also, Roger Bacon has laid down some excellent precepts for the conduct of life.[4] "Now, if you had such a biography of such a man now, you would know that without much difficulty you could find all his more important observations in print. So soon as he thought them important, he would communicate them to some society which would gladly publish them. In the first place, he would be glad to have the credit of an improvement, an invention, or a discovery. If the invention were likely to be profitable, the nation would secure the profit to him if he fully revealed the process. They would give him, by a 'patent,' the right to the exclusive profit for a series of years. The nation thus puts an end to the old temptation to secrecy, or tries to do so. "But if you will read some of the queer passages from the old lives of Bacon, you will see how very vague were the notions which the people of his own time had of what he was doing." Then Hester read some passages which Colonel Ingham had marked for her. OF THE PARENTS AND BIRTH OF FRYER BACON, AND HOW HE ADDICTED HIMSELF TO LEARNING.