GRAVES GRAVITY 175 on G 3t hotly contested of the war, the loss of le Germans being about 20,000 in killed and wounded, and that of the French, who occu- pied superior positions and acted on the defen- sive, about 13,000. GRAVES, a S. W. county of Kentucky, bor- dering on Tennessee, and drained by Mayfield creek and Obion river ; area, 515 sq. m. ; pop. in 1870, 19,398, of whom 2,329 were colored. It is traversed by the Paducah and Memphis railroad. The surface is level and the soil gen- erally productive. The chief productions in 1870 were 96,453 bushels of wheat, 842,445 of Indian corn, 24,424 of oats, 14,952 of Irish and 24,259 of sweet potatoes, 158,380 Ibs. of butter, 4,774,195 of tobacco, and 187 bales of cotton. There were 3,935 horses, 2,311 mules and asses, 3,681 milch cows, 4,404 other cattle, 13,876 sheep, and 31,570 swine ; 1 woollen factory, and 2 wool-carding and cloth-dressing estab- lishments.' Capital, Mayfield. GRAVES, Robert, an English engraver, born May 7, 1798, died in London, Feb. 28, 1873. He was the eldest son of Robert Graves, a noted connoisseur of rare prints, and the grandson of a printseller. Among his latest productions were a series of portraits from the works of Sir Joshua Reynolds and Gainsborough, and " is last work was the portrait of Charles Dick- after Frith. GRAVESANDE, Willem Jakob ran >s, a Dutch philosopher, born in Bois-le-Duc, Sept. 27, 1688, died in Leyden, Feb. 28, 1742. He published at the age of 18 an essay on perspective, and a philosophical thesis on suicide. After comple- ting his studies in the university of Leipsic in 1707, he was admitted to the bar at the Hague, where he wrote for the Journal Litteraire an examination of Fontenelle's " Geometry of the Infinite," a dissertation on the construc- tion of the air pump, one concerning the force of bodies, in which he embraced the opinion of Leibnitz against that of Newton, and dis- sertations upon the motion of the earth, &c. In 1717 he was appointed professor of mathe- matics and astronomy in the university of Leyden, and exchanged his chair in 1734 for that of philosophy, which he held till his death. His philosophical writings are eclectic in char- acter, combining portions of the doctrines of Locke, Descartes, and Leibnitz. His principal works are: Phy sices Elementa Mathematica (2 vols. 4to, the Hague, 1720-'23) ; Matheseos Universalis Elementa (8vo, Leyden, 1727) ; and Introductio ad Philosophiam, Metaphysi- cam et Logicam (Leyden, 1736-'7). GRAVESEND, a municipal borough, town, and river port of Kent, England, on the right bank of the Thames, 21 m. E. by S. of London ; pop. in 1871, 21,183. The principal public edifices are the town hall, parochial church (where Pocahontas is buried), literary institution, and theatre. Ship building is carried on to a con- siderable extent, but the chief trade arises from supplying outward-bound ships with stores and clothing. Gravesend is the limit of the port 372 VOL. viii.12 of London ; inward-bound vessels stop here for examination by the customs officers. GRAVIER, Jacques, a French missionary in America, died in 1708. Soon after his arrival in Canada, in 1684, he was sent to the Illinois region, where he followed up the labors of Mar- quette and Allouez among the Kaskaskias and other bands of the Illinois, and became the real founder of the mission, which he directed for many years, meeting much opposition from the medicine men, and receiving at their hands a wound which ultimately caused his death. He compiled a grammar of the Illinois, which was highly esteemed and formed the basis of all subsequent works of the kind. "When Iberville began the settlement of Louisiana, the Illinois prepared to go down the Mississippi ; but the Kaskaskias, the first to move, were induced by Gravier to halt at the place which now bears their name. He went down to confer with Iberville, and has left a journal of his canoe voyage. He descended again in 1706, and went to Europe. He returned in February, 1708, but must have reembarked, as he died at sea in April. Of his writings the following have been printed : Relation de ce qui tfest passe dans la mission de Vlmmaculee Conception au pays des Illinois 1693-'4 (8vo, New York, 1857) ; Relation ou Journal du voyage en 1700 depuis le pays des Illinois jusqu'd V embouchure du Mississipi (1859) ; Lettre sur les affaires de la Louisiane, fev. 23, 1708 (1865). GRAY INA, a town of S. Italy, in the province and 36 m. S. W. of the city of Bari, on a river of the same name, an affluent of the Bradano ; pop. about 14,000. It is the seat of a bishop, and has five churches and a gymnasium. It was unsuccessfully besieged by the Saracens in 975, GRAVINA, GiOTanni Vincenzo, an Italian jurist, born at Roggiano, Jan. 20, 1664, died in Rome, Jan. 6, 1718. Devoting himself to civil and canon law, he went to Rome in 1689, published several brief works on morals and literature, and in 1695, having collected 15 of his friends in his garden, formed the academy of the Ar- cadians. In 1699 he was appointed professor of civil law in the college of La Sapienza, and in 1703 of canon law. He soon after published his works on the " Origin of the Civil Law " and on the " Roman Empire." A schism took place in 1711 in the academy of the Arcadians, and Gravina and his friends withdrew and founded the Quirina academy. He was the adoptive father of Metastasio. GRAVITY, or Gravitation (Lat. granites, weight), in physics, the tendency of bodies to- ward each other or toward a centre of attrac- tion. In the article ASTRONOMY we have con- sidered the history of the discovery of the great law of gravitation, and have sketched the ap- plication of the law to elucidate a variety of problems of interest connected with the mo- tions of the celestial bodies; in the article EARTH we have considered the application of this law to determine the mass and figure of the earth ; and in dealing with the lunar mo-
