A.D. 1666.—Denys (William), hydrographer, of Dieppe, observes that the compasses placed in different parts of a vessel give different indications (Becquerel, “Magnétisme,” p. 119; “Journal des Sçavans” pour 1665 et 1666, p. 538).
A.D. 1671.—Richer (T.), French philosopher, who was sent by the Paris Academy of Sciences to the island of Cayenne for the purpose of determining the amount of terrestrial refraction and for other astronomical objects, is the first to make known the electrical powers of the gymnotus electricus.
References.—Leithead, “Electricity,” Chap. XII; Fahie, “El. Tel.,” p. 171; Bertholon, “Elec. du Corps Humain,” 1786, Vol. I. p. 171; Mém. de l’Acad. des Sciences, 1677, Art. VI; Richer, “Observations,” etc., Paris, 1679; Bancroft, at A.D. 1769; “Cosmos,” 1859, Vol. V. pp. 23–24.
A.D. 1671.—Rohault (Jacques), a French philosophical writer, and one of the earliest, ablest and most active propagators of the Cartesian philosophy in France, publishes at Paris the first edition of his “Traité de Physique,” at Part III. chap. viii. pp. 198–236 of which he treats especially of amber and of the loadstone. The same passages can be seen at Vol. II. part iii. chap. viii. pp. 163, etc., of Rohault’s “System of Natural Philosophy,” published in London during the year 1723, and at the same chapter, pp. 388, etc., of “Jacobi Rohaulti Physica,” Londini, 1718.
The latter is the last and best edition of the well-known classical translation, originally made in 1697, by Dr. Samuel Clarke, who was the friend of Sir Isaac Newton and chaplain to Bishop Moore, of Norwich. Through this work Clarke introduced very many critical notes exposing the fallacies of the Cartesian system. The “Physica” passed through four editions as the Cambridge University textbook before it was made to give way to the treatises of Newton.
A.D. 1672.—Sturm (John Christopher), a very able German mathematician, who was for thirty-four years professor of natural philosophy at the University of Altdorf (Franconia), and who, after vainly attempting to satisfactorily unite the Aristotelian and Cartesian doctrines finally adopted the Baconian philosophy, establishes the “Collegium Curiosum” on the plan of the celebrated Italian “Accademia del Cimento,” alluded to under the A.D. 1609 date.
The society was founded for the purpose of studying, repeating and even modifying the most notable philosophical experiments of the day, such as those made by Von Guericke, Boyle, Hooke and others, and its proceedings were published in 1676 and 1685 under the title of “Collegium Experimental sive Curiosum, etc.”
A.D. 1673.—Hevelius—Hevel—Hovel—Hövelke (Joannes), an eminent Polish astronomer, member of the English Royal Society, and a great friend more particularly of le Père M. Mersenne, of Gassendi and of Kircher, publishes during 1673 the first part of his great work “Machina Cœlestis”—dedicated to Louis XIV—the entire second part of which, issued in 1679, was destroyed by fire with the exception of seven copies. This explains its extreme scarcity. It was this work which led to the public controversy between Hevelius and Dr. Hooke who published, in London, during 1674 his “Animad. in Mach. Celest. Hevelii.”
It is said that, next to John Flamsteed, Hevelius was the most accurate observer of the heavens in his day (“The Reliquary,” London, Vol. XIV. pp. 149–159 and Vol. XV. pp. 34–38; “Journal des Savants” for March, June and November 1836). He had already published “De Variatione acus magneticæ” (Opusc. Act. Erudit. Lips., Vol. I. p. 103), also a report of the variations of the magnetical needle during 1670, which can be found in the Phil. Trans., Vol. V. for 1670, p. 2059, or in Hutton’s abridgments, London, 1809, Vol. I. p. 514.
References.—Larousse, “Dict.,” Vol. IX. pp. 266–267; “Biog. Gén.,” Vol. XXV. pp. 285–294; Delambre, “Hist. de l’Astron. Mod.,” Vol. II. pp. 434–484; Weidler, “Hist. Astron.,” p. 485; “Mem. Roy. Soc.,” 1739, Vol. I. p. 274.