an American physician, newspaper publisher, and geologist. He graduated from Yale College in 1824. After two or three years spent in school-teaching and in studying medicine, he established himself as a physician in Goshen, Conn. A year later he removed to Roxbury, Conn., and in 1831 to Richmond, Mass. Finding the exposure to the severity of the weather too ...

an American physician, newspaper publisher, and geologist. He graduated from Yale College in 1824. After two or three years spent in school-teaching and in studying medicine, he established himself as a physician in Goshen, Conn. A year later he removed to Roxbury, Conn., and in 1831 to Richmond, Mass. Finding the exposure to the severity of the weather too much for his rather delicate constitution, he gave up his profession (about 1837), and opened a boarding-school for boys in Richmond, in which he proved highly successful. In 1848 he removed to Pittsfield, Mass., to take charge of an agricultural warehouse and seed store, connected with a printing office from which a weekly agricultural and miscellaneous newspaper, the Berkshire Agriculturist, was published. This paper, which he renamed The Culturist and Gazette, he continued to edit until 1858, when its publication was suspended.

a notable chemist, geologist, metallurgist, naturalist, industrialist and philosopher, and a member of the prestigious Prussian Academy of Sciences. He is best known for his discoveries of several chemical products of economic importance, extracted from tar, such as eupione, waxy paraffin, pittacal (the first synthetic dye) and phenol (an antiseptic). He als...

a notable chemist, geologist, metallurgist, naturalist, industrialist and philosopher, and a member of the prestigious Prussian Academy of Sciences. He is best known for his discoveries of several chemical products of economic importance, extracted from tar, such as eupione, waxy paraffin, pittacal (the first synthetic dye) and phenol (an antiseptic). He also dedicated himself in his last years to research an unproved field of energy combining electricity, magnetism and heat, emanating from all living things, which he called the Odic force.

a German mathematician who made contributions to analysis, number theory, and differential geometry. In the field of real analysis, he is mostly known for the first rigorous formulation of the integral, the Riemann integral, and his work on Fourier series. His contributions to complex analysis include most notably the introduction of Riemann surfaces, breaki...

a German mathematician who made contributions to analysis, number theory, and differential geometry. In the field of real analysis, he is mostly known for the first rigorous formulation of the integral, the Riemann integral, and his work on Fourier series. His contributions to complex analysis include most notably the introduction of Riemann surfaces, breaking new ground in a natural, geometric treatment of complex analysis. His famous 1859 paper on the prime-counting function, containing the original statement of the Riemann hypothesis, is regarded, although it is his only paper in the field, as one of the most influential papers in analytic number theory.

a French mathematician, was born at Roberval near Beauvais, France. He worked on the quadrature of surfaces and the cubature of solids, which he accomplished, in some of the simpler cases, by an original method which he called the "Method of Indivisibles"; but he lost much of the credit of the discovery as he kept his method for his own use, while Bonaventur...

a French mathematician, was born at Roberval near Beauvais, France. He worked on the quadrature of surfaces and the cubature of solids, which he accomplished, in some of the simpler cases, by an original method which he called the "Method of Indivisibles"; but he lost much of the credit of the discovery as he kept his method for his own use, while Bonaventura Cavalieri published a similar method which he independently invented. Another of Roberval’s discoveries was a very general method of drawing tangents, by considering a curve as described by a moving point whose motion is the resultant of several simpler motions. He also discovered a method of deriving one curve from another, by means of which finite areas can be obtained equal to the areas between certain curves and their asymptotes. To these curves, which were also applied to effect some quadratures, Evangelista Torricelli gave the name "Robervallian lines."

a French lawyer , physicist, chemist and aeronaut. He met Jean-Francois Pilatre de Rozier in August 1784 and began studying a balloon capable of crossing the English Channel. A simple balloon does not allow a trip so long (it would be impossib...

a French lawyer , physicist, chemist and aeronaut. He met Jean-Francois Pilatre de Rozier in August 1784 and began studying a balloon capable of crossing the English Channel. A simple balloon does not allow a trip so long (it would be impossible to transport all the hay necessary for heating), they develop a combination of balloon and gas balloon , they call "aero-balloon." Roman built the balloon with his brother in Paris under the dome of the Tuileries.

a French physician and botanist noted for the 1536 publication in Paris of De Natura Stirpium, a Renaissance treatise on botany. Ruel was born in Soissons. He was self-taught in Greek and Latin, and studied medicine, graduating in 1508, or, according to other sources in 1502. In 1509 he became physician to Francis I, devoted himself at the same time to a st...

a French physician and botanist noted for the 1536 publication in Paris of De Natura Stirpium, a Renaissance treatise on botany. Ruel was born in Soissons. He was self-taught in Greek and Latin, and studied medicine, graduating in 1508, or, according to other sources in 1502. In 1509 he became physician to Francis I, devoted himself at the same time to a study of botany and pharmacology. He was a professor at the University of Paris, and a large part of his academic career was given to an analysis of Dioscorides' De Materia Medica, of which he published a Latin translation in 1516.