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 180 NAVARRO the " Voyage of the Sutil and Mexican on the Coasts of California" (1802). His Disertacion sobre la historia de la ndutica espanola was published in 1846, and his Biblioteca maritima espanola, in 2 vols., in 1851. NAVARRO, a N. E. county of Texas, bounded N. E. by the Trinity river, by branches of which it is drained; area, 1,040 sq. m. ; pop. in 1870, 8,879, of whom 2,245 were colored. It has a rolling surface, with a rich, dark soil along the watercourses, and a large portion of prairie. It is traversed by the Houston and Texas Central railroad. The chief productions in 1870 were 219,865 bushels of Indian corn, 5,150 of sweet potatoes, 4,077 bales of cotton, and 2,935 Ibs. of wool. There were 9,244 horses, 1,151 mules and asses, 4,875 milch cows, 2,459 working oxen, 32,783 other cattle, 7,144 sheep, and 16,419 swine. Capital, Corsicana. NAVEZ, Francois Joseph, a Belgian painter, born in Charleroi, Nov. 17, 1787, died in Brus- sels in 1869. He studied at Brussels, won a prize at Ghent, became a pupil of J. L. Da- vid in Paris, and subsequently visited Italy. On returning to Brussels he rapidly rose to be the most eminent master of the academi- cal school of painting, and became director of the academy of fine arts and professor in the normal school. Among his works are: "Hagar in the Desert," "Meeting of Isaac and Rebecca," " Raising of the Son of the Su- lamite Woman," " The Prophet Samuel," " The Ascension of the Virgin," "Marriage of the Virgin," "Jesus Sleeping," and "The Virgin and the Infant Jesus." NAVIGATION, the art or system of rules and practices by means of which vessels are direct- ed in their course upon the water. Prior to the invention of the mariner's compass naviga- tion was limited to enclosed seas like the Medi- terranean, to gulfs and archipelagos, and to the coasts. Beyond the sight of land, the mariner had no guide in cloudy nights, and no resource in stormy weather ; consequently, the most re- mote and venturesome expeditions only moved along the shore ; and the sea was avoided as much as possible, especially during the winter season, from the middle of November to the middle of March. The discovery of the mari- ner's compass changed this state of things en- tirely, by furnishing a never-failing guide, as useful and safe to the navigator in the night as during the day, and in storms as in fair weath- er. It is uncertain to whom the world is in- debted for the first observation of the directing powers of the magnet, and for their application to the purposes of travelling by land and sea. (See COMPASS.) The introduction to Church- ill's "Collection" contends for the honor of the discovery in behalf of Flavio Gioja of Pasi- tano, near Amalfi, in Campania. The date as- signed to Gioja's invention is about the begin- ning of the 14th century. There can be no doubt that to him belongs the merit of having invented something by which its adaptation to nautical purposes was very much promoted ; NAVIGATION but that it was used at sea before his time ap- pears from various passages in authors of an older date. It was known in China many cen- turies previous to its introduction into Europe, and was used in the eastern portion of the Mediterranean during the first half of the 13th century. When ships, carrying with them an unfailing guide to direct their course, began to traverse the great seas in all directions, the cross staff and the astrolabe furnished them with the means of measuring the altitude of the sun and stars, and thus of approximately determining the latitude and time. But the most serious inconvenience arose from the un- avoidable use of a plane chart to represent the sphere, the gross distortions and errors of which often misled the mariner, especially in voyages far distant from the equator. Recourse was had to globes to remove this evil, and a famous pair is mentioned which was made in 1592, under the direction of Mr. William Sanderson, a merchant, " commended for his knowledge as well as generosity to ingenious men." On the terrestrial one were described the voyages of Drake, Cavendish, and Frobisher. The plane chart, however, being so much more easy and convenient in practice, kept its place until the invention of the projection of the sphere upon a plane surface by Gerard Mercator, in 1569. Mercator's projection consists in keeping the meridians parallel, but augmenting the length of the meridians between the parallels of lati- tude, in receding from the equator, in such a manner that the just proportions of the merid- ians and parallels of latitude to each other are preserved. The signal advantage o.f this pro- jection is, that the directions of the compass, or what in technical language are called the "compass courses," are straight lines. The navigator works most conveniently upon a plane surface, and by means of Mercator's projection he is able to lay down his courses with a paral- lel rule, the points being taken from a compass drawn on the chart, and the line being one that cuts all the meridians at the same angle, and .marks the magnetic bearing of the objects through which it passes. This is called the rhumb line or loxodromic curve, and the defini- tion of it answers for the definition of the com- pass course. Such is the suitableness of Merca- tor's projection to the use of the mariner's com- pass, that the latter now seems to have been an incomplete discovery until the announcement of the former. It is suggested that Mercator arrived at his invention by simply observing on the globe where the meridians were cut at each par.allel of latitude by the rhumb lines ; and it is admitted that he never laid down, if he knew it, the mathematical theory on which it rests. This was first announced by Edward Wright, of Caius college, Cambridge. Shortly after this (1595), the famous navigator Capt. John Davis, who gave his name to the straits which he discovered, published a small treatise called " The Seaman's Secrets," at the end of which he gives a figure of a staff of his contrivance,