[117] In general these men acted before Baron wrote, or at any rate, before he wrote the _Novum Organum_, but the statement must not be taken too literally. The dates are as follows: Copernicus, 1473-1543; Tycho Brahe, 1546-1601; Gilbert, 1540-1603; Kepler, 1571-1630; Galileo, 1564-1642; Harvey, 1578-1657. For example, Harvey's _Exercitatio Anatomica de Motu Cordis et Sanguinis_ did not appear until 1628, and his _Exercitationes de Generatione_ until 1651. [118] Robert Hooke (1635-1703) studied under Robert Boyle at Oxford. He was "Curator of Experiments" to the Royal Society and its secretary, and was professor of geometry at Gresham College, London. It is true that he was "very little of a mathematician" although he wrote on the motion of the earth (1674), on helioscopes and other instruments (1675), on the rotation of Jupiter (1666), and on barometers and sails. [119] The son of the Sir William mentioned below. He was born in 1792 and died in 1871. He wrote a treatise on light (1831) and one on astronomy (1836), and established an observatory at the Cape of Good Hope where he made observations during 1834-1838, publishing them in 1847. On his return to England he was knighted, and in 1848 was made president of the Royal Society. The title of the work to which reference is made is: _A preliminary discourse on the Study of Natural Philosophy_. It appeared at London in 1831. [120] Sir William was horn at Hanover in 1738 and died at Slough, near Windsor in 1822. He discovered the planet Uranus and six satellites, besides two satellites of Saturn. He was knighted by George III. [121] This was the work of 1836. He also published a work entitled _Outlines of Astronomy_ in 1849. [122] While Newton does not tell the story, he refers in the _Principia_ (1714 edition, p. 293) to the accident caused by his cat. [123] Marino Ghetaldi (1566-1627), whose _Promotus Archimedes_ appeared at Rome in 1603, _Nonnullae propositiones de parabola_ at Rome in 1603. and _Apollonius redivivus_ at Venice in 1607. He was a nobleman and was ambassador from Venice to Rome. [124] Simon Stevin (born at Bruges, 1548; died at the Hague, 1620). He was an engineer and a soldier, and his _La Disme_ (1585) was the first separate treatise on the decimal fraction. The contribution referred to above is probably that on the center of gravity of three bodies (1586). [125] Habakuk Guldin (1577-1643), who took the name Paul on his conversion to Catholicism. He became a Jesuit, and was professor of mathematics at Vienna and later at Gratz. In his _Centrobaryca seu de centro gravitatis trium specierum quantitatis continuae_ (1635), of the edition of 1641, appears the Pappus rule for the volume of a solid formed by the revolution of a plane figure about an axis, often spoken of as Guldin's Theorem.