548 



TELESCOPE CARP TELLURIUM. 



scopes, we now return to the refracting one. The 

 most important improvement in this instrument 

 consists in the formation of the object-glasses free 

 from the errors of chromatic and spherical aberra- 

 tion, whence they have been denominated achro- 

 matic (, without ; xw, colour) telescopes, or, 

 more properly, aplnnatic (, without ; >., 

 error) telescopes. These are now made in such 

 perfection, that they have, in some degree, super- 

 seded the reflecting telescopes ; and the optical 

 institute at Benedictbeuern provides observatories 

 with such excellent dioptrical instruments, that the 

 catoptric are little used. Dollond first made achro- 

 matic telescopes ; Ramsden, Reichenbach, &c., 

 have made the best. They are formed by employ- 

 ing a double object-glass, composed of two lenses 

 of different refractive powers, which will mutually 

 correct each other, and thus give a pencil of white 

 light entirely colourless. Triple object-glasses are 

 also used : one of the largest ever constructed was 

 erected at the observatory of Dorpat, in 1824, 

 and was made by Fraunhofer. The diameter of 

 the object-glass has a clear aperture of nine and six 

 tenths inches, and a focal distance of fifteen feet ; 

 but he afterwards constructed another, with a 

 diameter of twelve Paris inches, and a focus of 

 eighteen feet. Mr Tully has also made one in 

 England, of which the aperture of the object-glass 

 is six eight-tenth inches, and the focal length 

 twelve feet. It is now in possession of doctor 

 Pearson. See Astronomical Transactions, vol. ii. 



TELESCOPE CARP. See Gold-Fish. 



TELL, WILLIAM, a peasant of Biirgeln, near 

 Altorf, celebrated for his resistance to the tyranny 

 of the Austrian governor Gessler or Gassier. 

 Switzerland consisted of a great number of secular 

 and ecclesiastical districts, belonging partly to the 

 hereditary dominions of the house of Hapsburg, 

 and partly to the German empire. Albert I., em- 

 peror of Germany, a grasping prince, eager to make 

 territorial acquisitions, wished to unite the Forest 

 Towns with his hereditary estates, and proposed 

 to them to renounce their connexion with the 

 empire, and to submit themselves to him as duke 

 of Austria. They rejected his offers, and were in 

 consequence so ill treated and oppressed by the im- 

 perial governors, that, in 1307, Uri, Schweitz, and 

 Underwalden formed a league, under the influence 

 of three brave men, Walter Furst (Tell's father-in- 

 law), Arnold of Melchthal, and Werner Stauffacher. 

 Tell was also one of this league. Gessler now pushed 

 his insolence so far as to require the Swiss to un- 

 cover their heads before his hat (as an emblem of 

 the Austrian sovereignty), and condemned Tell, 

 who refused to comply with this mandate, to shoot 

 an apple from the head of his own son. Tell was 

 successful in his attempt, but confessed that a se- 

 cond arrow, which he bore about his person, was 

 intended, in case he had failed, for the punishment 

 of the tyrant, and was therefore retained prisoner. 

 While he was crossing the lake of the Four Cantons, 

 or lake of Lucerne, in the same boat with Gessler, 

 a violent storm threatened the destruction of the 

 skiff. Tell, as the most vigorous and skilful helms- 

 man, was set free ; and he conducted the boat suc- 

 cessfully to the shore, but seized the opportunity to 

 spring upon a rock, pushing off the barque. He 

 had fortunately taken his bow with him ; and when 

 the governor finally escaped the storm, and reached 

 the shore,, Tell shot him dead, on the road to Kiis- 

 snacht. The death of Gessler was a signal for a 

 general rising, and a most obstinate war between 



the Swiss and Austria, which was not brought to a 

 close until 1499. (See Switzerland.) Tell was 

 present at the battle of Morgarten (q. v.\ and is 

 supposed to have lost his life in an inundation in 

 1350. Such is the story of William Toll, which, 

 attested by chapels, by the designation of the rock 

 on which he leaped, by paintings and other circum- 

 stances, has been called in doubt by many, but is 

 sanctioned by John von Miiller. Saxo Grammati- 

 cus relates a similar story of a Danish king, Harold, 

 and a certain Tholko ; but the tradition might have 

 been transmitted from Germany to the north by 



means of the Hanse towns See Hagen's Northern 



Heroic Romances, in German (Breslau, 1814). 

 There is one circumstance which may be considered 

 sufficient to attest the truth of the main points of 

 Tell's history. After the expulsion of the governors, 

 and the demolition of their castles, it became cus- 

 tomary among the Swiss to make pilgrimages to 

 the place where Tell had leaped ashore; and in 

 1388, thirty years after his death, the canton of Uri 

 erected a chapel (called Tell's chapel") on the rock 

 upon which he had sprung, and caused a eulogy to 

 be pronounced every year in memory of him. In 

 the same year the spot was visited by 114 persons, 

 who had been acquainted with Tell. All the old 

 chronicles agree on this point ; and Schiller, in his 

 tragedy of William Tell, has accurately copied the 

 accounts of Tschudi and Miiller. See Balthasar 

 and Haller's Defence of William Tell (1772, new 

 edition, 1824), and Hisely's Dissertatio de Gul. 

 Tellio (Groningen, 1824). 



TELLIER, FKAN90IS MICHEL LE. See Louvois. 



TELLIER, MICHEL LE, a distinguished Jesuit, 

 was born in 1643, near Pere, in Lower Normandy. 

 He studied in the Jesuits' college at Caen, and en- 

 tered the society at the age of eighteen. In 1709, 

 he was chosen confessor to Louis XIV. He was a 

 bitter enemy of the Jansenists ; and his first act 

 was the demolition of the celebrated house of the 

 Port Royal. He then forced upon the nation the 

 bull Unigenitus. (q. v.) His violence was the 

 cause of much of the odium which the Jesuits soon 

 after experienced, and paved the way for the aboli- 

 tion of their society. On the death of Louis, he 

 was exiled, first to Amiens, and afterwards to La 

 Fleche, where he died, in 1719. 



TELLURISM. See Magnetism, Animal. 



TELLURIUM ; the name of a metal discovered 

 in 1782, and named by Klaproth from the earth in 

 1798. We shall first describe its ores. There are 

 four: 1. Native tellurium. It is of a tin-white 

 colour, passing into lead-gray, with a shining, me- 

 tallic lustre. It occurs in minute hexagonal cry- 

 stals, possessed of regular cleavages ; but their 

 direction, owing to the minuteness of the crystals, 

 has not been detected. It occurs also in crystal- 

 line grains, either aggregated, solitary, or dissemi- 

 nated. It yields to the knife, and is brittle ; specific 

 gravity 5'7 6-1. Exposed to the blow-pipe, it 

 melts before ignition, and, on increasing the heat, 

 it burns with a greenish flame, and is almost en- 

 tirely volatilized in a dense white vapour, with a 

 pungent, acrid odour, like that of horse-radish. It 

 consists of tellurium 92-55, iron 72, gold 0-25. It 

 has been found chiefly in Facebay, in Transylvania. 

 2. Graphic tellurium, or graphic gold. It is of a 

 steel-gray colour, generally splendent, but some- 

 times slightly tarnished externally. It occurs cry- 

 stallized in the form of a right rhombic prism of 

 107 44'. The crystals are commonly so arranged 

 as to give to the whole row the appearance of a 



