Public business and long years of diplomatic service interrupted the original study of science to a great extent; but even so, in England, in France, and in the closing years of his life in Philadelphia, Franklin found time, now and then, to devote to that loving investigation of Nature, which, after his thirtieth year, became the great passion of his life.
Everything in the way of scientific research fascinated him: he investigated earthquakes, eclipses, storms, winds, the science of sound, the laws of hot air and its movements, ventilation, water-spouts, phosphorescence (“light in sea-water,” he called it), the cause of saltiness in the sea, the Gulf Stream, rainfall, evaporation, the aurora borealis, light, heat, the daily motion of the earth, and many other subjects. He studied music as a science, and invented a new kind of musical glasses (fashionable at that time) called “Armonica.” He studied political economy in a scientific way, and was so interested in agriculture that he tried experiments on his New Jersey farm. He also invented the “Pennsylvania fireplace” and the “Franklin” stove. Though his scientific writings are numerous, they are in the form of essays and letters. His investigations and experiments were thus made known to the world in letters to friends in France and England; for, as there were no scientific periodicals in those days, men of learning kept up a lively correspondence and occasionally issued a pamphlet.
PREPARED BY THE EDITORIAL STAFF OF THE MENTOR ASSOCIATION
ILLUSTRATION FOR THE MENTOR. VOL. 6. No. 7. SERIAL No. 155
COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.
FROM THE ORIGINAL PAINTING BY CHAPPEL
DRAFTING THE DECLARATION OF INDEPENDENCE—FRANKLIN, JEFFERSON, ADAMS, LIVINGSTON, SHERMAN
BENJAMIN FRANKLIN
As Man of Letters
FIVE
