Parrot, Roger Bacon et ses contemporains (1894); E.
Diagrams illustrating the division of the world into climata, are to be found in the opus majus of Roger Bacon (d.
Des Roger Bacon (Vienna, 1879); S.
He seems to have been the grandnephew of Roger Bacon (Brit.
Des Roger Bacon and Die Kosmologie.
That Roger Bacon was acquainted with the principle of the camera obscura is shown by his attempt at solving Aristotle's problem stated above, in the treatise De Speculis, and also from his references to Alhazen's experiments of the same kind, but although Dr John Freind, in his History of Physick, has given him the credit of the invention on the strength of a passage in the Perspectiva, there is nothing to show that he constructed any instrument of the kind.
The descent of alchemistical doctrine can thus be traced with fair continuity for a thousand years, from the Greeks of Alexandria down to the time when Latin alchemy was firmly established in the West, and began to be written of by historical authors like Albertus Magnus, Roger Bacon and Arnoldus Villanovanus in the 13th century.
As the benefactor and protector of Roger Bacon he has a special title to the gratitude of posterity.
Among the keenest critics of the Schoolmen and of the recent translations of Aristotle was Roger Bacon (d.
From the midst of the Franciscans who had persecuted Roger Bacon because he presumed to know more than was consistent with human humility arose John of Parma, adopting and popularizing the mystic prophecy of Joachim of Flora.