TACHYGRAPHY -TADPOLE. 



507 



apatite; specific gravity 2-8; composition lamellar, 

 generally longish, and strongly coherent. It is 

 composed of 



Silex, 

 J>ime, 

 Mechanical admixtures, 



51-60 



46-41 



1-11 



Before the blow-pipe, it melts on the edges into a 

 semi-transparent colourless enamel. By fusing 

 lime and silex in the requisite proportions, cleav- 

 able masses of the present species have been ob- 

 tained. It was first found at Cziklowa, near 

 Prawitza, in the Bannat of Temeswar, in several 

 copper mines. In Finland, it occurs in limestone, 

 at Edinburgh in greenstone at Castle hill, and in 

 Ceylon along with garnet. In the United States, 

 at Willsborough, New York, upon lake Champlain, 

 a vein of it, mixed with garnet, several feet in 

 width, appears to cross a mountain of gneiss. It 

 has been found abundantly near Grenville, in 

 Canada, and at East on, in Pennsylvania. A variety 

 of the present species, from Capo di Bove, near 

 Rome, was first called Woollastonite, but is now 

 known to belong to tabular spar. 



TACHYGRAPHY, or TACHEOGRAPHY. 

 See Stenography. 



TACITUS, CAIDS CORNELIUS, was descended 

 from a plebeian branch of the celebrated Cornelian 

 family, and was probably born at the close of the 

 reign of Claudius, or in the beginning of that of 

 Nero. Of his education and early life we know 

 little. He seems to have been first appointed to 

 public office in the reign of Vespasian, when, ac- 

 cording to a statement of the elder Pliny, he was 

 named procurator of Belgic Gaul. On his return 

 to Rome, he was treated with distinguished favour 

 by Titus, and was created questor or edile. He 

 himself alludes to this circumstance, but in very 

 general terms, in his works. In the reign of 

 Domitian, he became pretor (A. D. 88), and one of 

 the quindecemviral college, whose duty it was to 

 superintend the sacrifices. Disgusted with the 

 tyranny of Domitian, Tacitus left Rome on the 

 death of his father-in-law Julius Agricola, but again 

 returned, after the murder of that monster, to live 

 under the mild government of Nerva. The latter 

 rewarded his services with the consulship, A. D. 97. 

 He lived in the closest intimacy with the younger 

 Pliny, and had a very extensive practice in the 

 profession of law, acquiring a high reputation as an 

 orator. His domestic circumstances were no less 

 favourable : his wife, the daughter of Julius Agri- 

 i-ola, was distinguished among the Roman ladies of 

 tlie time for her virtues; and it seems probable 

 that the emperor Tacitus was a descendant of the 

 great historian. The time of his death is uncer- 

 tain ; but it probably took place during the reign 

 of Adrian. We have four historical works from his 

 pen. His Annals contain an account of the prin- 

 cipal events from the death of Augustus to that of 

 Nero, a period of fifty-four years. Books 6th to 

 10th inclusive are lost: the first five books were 

 discovered only 300 years ago, by the treasurer of 

 Leo X., in the monastery of Corvey. His History 

 (of which only four books, and a part of the fifth, 

 are extant) begins with the year 69 A. D., when 

 Galba wore the purple, and ends with the accession 

 of Vespasian (71). His Germany (De Situ, Mori- 

 bus et Populis Germanics'), and his life of Agricola, 

 are his only other historical works. The Dialogue 

 on the Decline of Eloquence is by some attributed 



to him. (See Quintilian.} The works of this 

 writer have been pronounced, by the unanimous 

 voice of his contemporaries and of posterity, the 

 masterpieces of a great mind. Racine declares him 

 to be the greatest painter of antiquity ; and, ac- 

 cording to Gibbon, he was the first historian who 

 applied the science of philosophy to the study of 

 facts. Independently of the value of his matter, 

 which is of the highest importance, from the facts 

 and profound views of Roman history, during the 

 first half century of the Christian era, which it, 

 affords, his writings are incomparable, considered 

 as works of art. In the choice and disposition of 

 his materials, we recognise the comprehensive 

 genius of a scholar, and the forming hand of an 

 artist, bringing out order and unity in the midst of 

 confusion, and grouping the complicated details 

 of life and manners in artful and expressive pictures. 

 In drawing the character of men and events, he 

 displays a wonderful acuteness and strength ; while, 

 amidst the corruption of a degenerated and vicious 

 age, he maintains the elevation of a virtuous mind. 

 His extreme conciseness has no appearance of affec- 

 tation, but seems to be dictated by the peculiarity 

 of his temper and feelings. His style is forcible, 

 but there is nothing laboured in his expressions, 

 nothing superfluous in his delineation ; the colours 

 are used sparingly, but the light and shade are dis- 

 posed with masterly skill. Among the best editions 

 of his works are those of Gronovius (Amsterdam, 

 1685, and Utrecht, 1729), of Brotier (Paris, 1771, 

 4to., and 1776, 12mo.), of Ernesti (Oberlin's, 

 Leipsic, 1801), and of Panckoucke (Paris, 1827, 

 folio.) The whole of Tacitus has been translated 

 into English by Murphy and by Gordon. 



TACKING, in navigation. See Ship. 



TACKLE ; a machine formed by the communi- 

 cation of a rope with an assemblage of blocks, and 

 known, in mechanics, by the name of pulley. 

 Tackles are used in a ship to raise, remove, or 

 secure weighty bodies, to support the masts, or to 

 extend the sails and rigging. They are movable, 

 as communicating with a runner, or fixed, as being 

 hooked in an immovable situation ; and they are 

 more or less complicated in proportion to the effects 

 which they are intended to produce. The applica- 

 tion of the tackle to mechanical purposes is called 

 hoisting, or bowsing. Ground tackle implies the 

 anchors, cables, &c. 



TACKSMEN. See Clan. 



TACTICS PROPER is the branch of military- 

 science which relates to the conduct of troops in 

 battle. Elementary tactics teaches the preparation 

 of them for it by instruction in military exercises: 

 hence every species of troops, as cavalry, artillery, 

 light and heavy infantry, &c., has its peculiar 

 tactics. Since the French, or, we may say, since 

 the American, revolution, tactics have undergone 

 an essential change. In recent times, a difference 

 has been made between strategy and tactics. (See 

 the articles Military Sciences, and Strategy. The 

 word is derived from **/*, which comes from 

 ra.r'e( (ordered, placed, commanded). 



Tactics, Naval. See Navigation, Navy, arid 

 Ship. 



TADMORE. See Palmyra. 



TADPOLE ; the young produced from the eggs 

 of the frog, which is extrerrely unlike the animal 

 in its perfect state, seeming to consist only of a 

 head and tail. The head is large, black, and round- 

 ish, the tail slender, and margined with a broad, 

 transparent fin. Its motions are very lively. Its 



