GONG GONSALVO. 



505 



GONG, a Chinese instrument of music, is a shal- 

 low kettle, three inches deep, made of an alloy of 

 tin, bismuth, and copper, and is struck with a wooden 

 mallet covered with leather. The sound is very loud. 



GONGORA, Louis, a celebrated Spanish poet, 

 was born at Cordova in 1562. He was educated for 

 the church, and was made chaplain to the king, and 

 a prebendary in the cathedral of Cordova. His 

 works have been published in one volume, quarto, 

 under the title of Obras de Dom. Louis de Gongora y 

 Argore. They consist chiefly of lyrical poems, in 

 which he excelled, being called by his countrymen 

 tlie prince of lyric poets. His style, however, is often 

 difficult to comprehend, even to the Spaniards them- 

 selves, and he has had almost as many censurers as 

 admirers in his own country. He died in 1627. 



GONIOMETER, any instrument for measuring- 

 angles, but more particularly the angles formed by 

 the faces of crystals. The goniometer employed by 

 Hauy was very simple in construction, but by no 

 means adequate to take minute measurements. It 

 consisted of a brass semicircle, divided into degrees, 

 similar to the common protractor. The extremities 

 of the arc ACB were joined by a brass 

 straight edge AB, on which an axis was 

 fixed at D the centre of the arc ACB. 

 An arm CE moved round this centre, 

 and the crystal being placed at the 

 angle ADE, with one of its faces ap- 

 plied to the edge AD, the arm was moved on its 

 axis till the edge DE was applied to the contiguous 

 face of the crystal. Then the point C indicated the 

 angle of inclination, or rather the supplement of that 

 angle. Even in practised hands tliis instrument 

 could not be depended upon for correct measures to 

 within two or three degrees ; and, as the science of 

 crystalography depended upon the accuracy of these 

 measurements, philosophers applied themselves to 

 the construction of more perfect goniometers. Dr 

 Wollastou's goniometer, which is most commonly in 

 use, operates upon optical principles, and is repre- 

 sented in the annexed engraving. It consists of a 

 brass circle graduated 

 into degrees on the edge, 

 and furnished with a no- 

 nius, c, so that angles can 

 be measured correct to 

 one minute. The circle 

 has a vertical motion 

 upon an axis, supported 

 by a stand as shown in 

 the engraving. This 

 axis is in the form of a 

 tube, and contains within 

 it a smaller axis which 

 may either be turned round with or without the axis 

 of the circle, as may be required. In order that 

 these axes may be turned with facility, the small one 

 is furnished with a milled head a, and the large one 

 with a milled head b, by which arrangement, when 

 the small one is held and the large one turned, the 

 circle will move round independent of the small axis, 

 and by holding the large milled head while the 

 smaller is turned, then the smaller axis will move in- 

 dependent of the circle ; and the one axis is fitted so 

 tightly into the other, that, when one milled head is 

 turned round, while the other is untouched, both axes 

 will move together. The crystal to be examined is 

 fastened on a kind of universal joint at x, capable ot 

 being placed in different positions by means of screws, 

 and carried round on the end of the smaller axis. 

 The crystal to be examined is attached to the end of 

 the joint at # by means of sealing wax, and placed in 

 such a position that its edge shall be parallel to the 

 axis of motion. The smaller axis is HOW turned 



round, while the eye is kept steadily at about an inch 

 distant until the bar of a window, or some other 

 object is reflected from the surface of the crystal. 

 The smaller axis is kept in this position, while the 

 circle is turned round so that or 180, shall be set 

 at an index fixed in the stand. The circle is then 

 turned round, along with the smaller axis, until the 

 next side of the crystal comes to the same position 

 as the first j that is, where it reflects the same object 

 to the eye in the same situation as before. The arc 

 passed through by the circle, will be the supplement 

 of the angle formed by the two faces of the crystal; 

 but it is so graduated that no calculation is required, 

 the angle itself being pointed out. This instrument 

 is well fitted for measuring the angles of small 

 crystals, and with a little care, the measures may be 

 taken with sufficient minuteness, for all practical 

 purposes. Malus converted this goniometer into a 

 repeating circle, but with wliat advantage it is not 

 easy to see, since a repeating instrument implies a 

 degree of minuteness in measurement, in most cases 

 unattainable in the angles of crystals. Dr Brewster 

 has contrived a goniometer on optical principles much 

 more complex in its construction than the instru- 

 ment of YVollaston, but capable of measuring hollow 

 angles as well as solid, but it would be out of place 

 in a work of this nature to give an account of this 

 ingenious contrivance. 



GONSALVO, HERNANDEZ Y AQUILAK, DE COR- 

 DOVA, called the great captain (el gran capitan), was 

 born at Montilla, near Cordova, in 1443, and, when 

 fifteen years of age, served under his father, don 

 Diego, against the Moors of Granada. As a reward 

 of his bravery, Henry IV., king of Castile, intrusted 

 him with the command of a company, with which he 

 spread terror to the very gates of Malaga, and in 1460, 

 decided the victory of Las Yeguas. The king him- 

 self knighted him on the field of battle. From 1458 

 to 1467, he served with distinction against the Moors, 

 at the capture of Gibraltar and in the Catalonian 

 war. After the death of Henry, Ferdinand and 

 Isabella having ascended the throne, and the king of 

 Portugal having declared war against them, Gon- 

 salvo contributed not a little to the victory of Toro, 

 in 1476. In the bloody war of Granada he took 

 many places by storm, and vanquished the boldest 

 Moors who dared to meet him in single combat. 

 Granada finally submitted, and, on the entry of the 

 conquerors, he was appointed to carry the flag ot 

 Castile. Ferdinand then sent him with 5600 men 

 to assist his relative, Frederic king of Naples, 

 against the French. Having secured that throne, 

 he returned to Spain, where he was engaged in sub- 

 jecting the Moors, in the Alpuxarras, when Louis 

 XII. of France, renewed the war against Naples. In 

 1500 Gonsalvo again set sail with a corps of 4300 men, 

 ostensibly to assist the Venetians against the Turks. 

 He delivered Zante and Cephalonia from the infidels, 

 and restored them to Venice. He then landed in 

 Sicily, and informed the king of Naples that he was 

 come to secure that part of the kingdom which, by 

 virtue of the treaty with Louis XII., had fallen to 

 Spain. Frederic, finding himself so closely pressed 

 by two enemies, finally retired with his treasures into 

 an island. The French, under the duke of Nemours, 

 entered Naples, while Gonsalvo secured Calabria, 

 and, according to the articles of the treaty, demanded 

 also Basilicata and Capitanata. To this the French, 

 who considered them as belonging to their part 

 (Abruzzo), would not consent. The result was a war 

 between France and Spain, which was carried on with 

 a variety of fortune, until Gonsalvo, by the victory 

 near Seminara in 1 502, obtained possession of both 

 Calabrias. In 1503, he gained a still more important 

 victory near Cerignola, in consequence of which 



