Ad clar. v. d. Schonerum de libris revolutionism eruditiss. viri et mathemattci excellentiss. Rev. Doctoris Nicolai Copernici Torunnaei, Canonici Warmiensis, per quemdam juvenem mathematico studio sum, Narratio prima, Dantzic, 1540. This was the first published statement of the doctrine of Copernicus, and was a letter published by Rheticus. Three years afterwards Copernicus's De orbium colestium revolutionibus, Libri VI., was published at Nuremberg (1543). Descartes, René. See vol. ii., p. 193. Traité de Vhomme (Cousins's edition, in 11 vols., Paris, 1824). Galilei, Galileo. See vol. ii., p. 91. Dialogo dei due massimi sistemi del mondo, Florence, 1632. Discorsi e dimostrazioni matematiche intorno a due nuove scienze, Leyden, 1638. Gilbert, William (1540-1603). See vol. ii., p. 113. De magnete, magneticisque corporibus, et de magno magnete tellure, London, 1600. De magnete was trans. by P. Fleury Motteley, London, 1893. Guericke, Otto von (1620-1686). See vol. ii., p. 213. Expérimenta nova, ut vocant, Magdeburgica de vacuo spatio, Amsterdam, 1672. In the Phil. Trans, of the Royal Society of London, No. 88, for 1672. Hales, Stephen (1677-1761). See vol. ii., p. 298. Statical Essays, comprising Vegetable Staticks, London, 1727, and Homostatics, London, 1733. Harvey, William. See vol. ii., p. 169. Exercitatio anatomica de motu cordis et sanguinis, Frankfort-on-Main, 1628. The Works of, trans, by Robert Willis, London, 1847. Hauksbeb, Francis. See vol. ii., p. 259. Physico-Mechanical Experiments on Various Subjects, London, 1709. This contains descriptions of his various discoveries in electricity, many of which are given in the Phil. Trans. Hooee, Robert. See vol. ii., p. 215. Micrographia, or Some Philosophical Descriptions of Some Minute Bodies, London, 1665. An Attempt to Prove the Motion of the Earth, London, 1674. Microscopical Observations, London, 1780. Most of Hooke's important discoveries were contributed as papers to the Royal Society and are available in the Phil. Trans. Huygens, Christian (1629-1695). See vol. ii., p. 218. Traite de la lumière, Leyden, 1690. Complete works were published at The Hague in 1888, under thetit le Ouvres complètes, by the Société Hollandaise des Sciences. These books have not been translated into English. Huygens's famous paper on the laws governing the collision of elastic bodies appeared in the Phil. Trans, of the Royal Society for 1669. Kepler, Johann. See vol. ii., p. 70. Astronomia nova de motibus Stella Mortis, Leipzig, 1609, contains Kepler's two first laws; and Harmonices mundi, 1619, contains the third law, Phomomenon singulare, seu Mercurius in sole, Leipzig, 1609. Joannis KepUri opera omnia, in 8 vols., Frankfort, 1858-1871. Leeuwenhoek, Anthony van. See vol. ii., p. 179.