In his book on Botany he treats of the organic structure and physiology of plants so accurately as to draw from Meyer, a botanist of the nineteenth century, this appreciative tribute. "No botanist who lived before Albert can be compared to him unless Theophrastus, with whom he was not acquainted: and after him none has painted nature with such living colors or studied it so profoundly until the time of Conrad Gesner and Cesalpino"--a high compliment indeed for Albertus for leadership in science for three centuries. To quote Von Humboldt again, "I have found in the book of Albertus Magnus, De Natura Locorum, considerations on the dependence of temperature concurrently on latitude and elevation and on the effect of different angles of incidence of the sun's rays in heating the ground, which have excited my surprise." Albertus Magnus gains renown also from his distinguished pupil Roger Bacon who, some think, should have the honor of being regarded as the father of inductive science--an honor posterity has conferred upon another of the same family name who lived 300 years later. We, who wear eye-glasses would be willing, I think, to vote the honor to the elder Bacon, because if we do not owe to him the discovery of lenses, we are his debtors for his clarification of the principles of lenses and for his successful efforts in establishing them on a mathematical basis. In any event, he was a pioneer in inductive science. Before gunpowder is known to have been discovered in the West, the friar Roger Bacon must have made some interesting experiments along the line of explosives, else he could not have made the following remarkable statement as to the property of gunpowder: "One may cause to burst from bronze, thunderbolts more formidable than those produced by nature. A small quantity of prepared matter causes a terrible explosion accompanied by a brilliant light. One may multiply this phenomenon so far as to destroy a city or an army." Anticipating the use of even motor boats and automobiles driven by gasoline, this thirteenth century scientist wrote: "Art can construct instruments of navigation such that the largest vessels governed by a single man will traverse rivers and seas more rapidly than if they were filled with oarsmen. One may also make carriages which, without the aid of any animal, will run with remarkable swiftness." This man whose clarity of vision anticipated those discoveries of the nineteenth century, left three disciples after him,--John of Paris, William of Mara and Gerard Hay--who followed their master's methods, especially of testing by observation and by careful searching of authorities, every proposition that came up for study.