115S THERA. {X^P"', Herod, iv. 153.) Ptolemy (iii. 15. § 26) }i:is preserved the names of two places, Eleusiii or Eleusis, and Oea; and a third, called Melaenae, occurs in an inscription. (Bijckh, Inscr. no. 2448.) Like Melos, Thera sided with th« Lacedaemonians at the commencement of the Peloponnesian War (Thuc. ii. 9), but of its subsequent history we have no information. Thera and the surrounding islands are remarkable as having been the scene of active volcanic operations in ancient as well as in modern times. In con- sequence of the survey made by command of the English Admiralty, we now possess precise infor- mation respecting these islands, the result of which, with additional particulars, is given by Lieutenant Leycester in a paper published in the Journal of the Koyal Geographical Society, from which the following account is chiefly taken. Thera, now called Santoriii, the largest of the group, lias been likened in form to a horse-shoe; but a crescent with its two points elon- gated towards the west would be a more exact de- scription. The distance round the inner curve is 12 miles, and round the outer 18, making the coast-line of the whole island 30 miles : its breadth is in no part more than 3 miles. Opposite to Thera west- ward is Therasia, which still bears the same name. (Strab. i. p. 57, v. p. 484; Steph. B. s. v. Qripaaia ; Ptol. iii. 15. § 28; Plin. ii. 87. s. 89, iv. 12. s. 70.) Its circuit is 7^ miles, its length from N. to S. about 2^ miles, and its breadth a mile. About If mile S. of Therasia, lies Aspronisi, or White Island, only a mile in circuit, and so called from being capped with a deep layer of pozzolana : the name of this island is not mentioned by the ancient writers. These three islands, Thera, Therasia, and Aspronisi, enclose an expanse of water nearly 18 miles in circumference, which is in reality the crater of a great volcano. The islands were origin- ally united, and were subsequently separated by the eruption of the crater. In the centre of this basin three volcanic mountains rise, known by the name of Kammeni or the Burnt, {Kaixfj-ivT) , i. e. Kav/xevT) instead of KeKav^ivy]), and distinguished as the Falaea or Old, the Nea or New, and the uMiha or Little. It was formerly asserted that the basin was unfathomable, but its depth and shape have been clearly ascertained by the soundings of the English Survey. Supposing the basin could be drained, a gigantic bowl-shaped cavity would appear, with walls 2449 feet high in some places, and no- where less than 1200 feet high, while the Kam- meiiis would be seen to form in the centre a huge mountain 5,^ miles in circumference with three sunnnits, the Palaea Kammeni, the Nea Kammeni, and the Mikra Kammtni, rising severally from the bottom of the abyss to the height of 1606, 1629, and 1550 feet. The rim of the great crater thus exposed would appear in all parts unbroken, except at the northern point between Thera and Therasia, where there is a chasm or door into the crater about a mile in width, and 1170 feet in depth midway between the two islands. (See Map, B.) If we now suppose the waters of the Aegaean let in, the edges of the crater, forming the inner curve of Thera and Therasia, rise above the sea from the lieight of 500 to 1200 feet, and present frightful precipices, of the colour of iron dross, except where their summits are capped with a deep layer of poz- zolana. The Palaea Kammeni is 328 feet above the water; the Nea Kammeni 351 feet; and the Mikra Kammeni 222 feet. THERA. Thera, Therasia, and Aspronisi are all composed of volcanic matter, except the southern part of Thera, which contains Mount EUas, of limestone formation, the peak of which rises 1887 feet above the level of the sea, and is the highest land in the island. This mountain must have been originally a submarine eminence in the bed of the Mediterranean before the volcanic cone was formed (Lyell, Prin- ciples of Geology, p. 445. 9th ed ). The first appearance of the three Kammenig be- longs to historical times, and has been narrated by several writers. The Nea Kammeni, which is the largest of the group, did not emerge till the year 1707; but the other two were thrown up in ancient times. The exact time of their appearance, how- ever, is diflerently related, and it is difiicult, and in some cases impossible, to reconcile the conflicting statements of ancient writers upon the subject. It appears certain that the oldest of these islands is the most southerly one, still called the Palaea or Old u Kammeni. It burst out of the sea in b. c. 197, and received the name of Hiera, a name frequently given in antiquity to volcanic mountains. This fact is stated by Eusebius, Justin, Strabo, and Plutarch. It is related by Strabo that flames burst out of the sea for four days, and that an island was formed 12 stadia or 1^ English mile in circumference. (Euseb. Chron. p. 144, Oli/mp. 145. 4; Justin, xxx. 4; Strab. i. p. 57; Plut. de Pyth. Or. 11. p. 399.) The unanimous statement of these four writers is, however, at variance with that of Pliny (ii. 87. s. 89), whosays"that iu the 4th year of the 135th Olympiad [e. c. 237] there arose Thera and Therasia; between these islands, 130 years later [b. c. 107], Hiera, also called Automate; and 2 stadia from the latter, 110 years [a. d. 3] afterwards, in the con- sulship of M. Junius Silanus and L. Balbus, on the 8th of July, Thia." In another passage he says (iv. 12. s. 23): " Thera, wiien it first emerged from the sea, was called Calliste. Therasia was after- wards torn away from it ; between the two there pre- sently arose Automate, also called Hiera; and in our age Thia near Hiera." Seneca refers apparently to the events mentioned by Pliny, when he states {Qu. Nat. ii. 26), upon the authority of Posidonius, that an island arose in the Aegaean sea " in the memory of our ancestors" (majorum nostrorum memoria), and that the same thing happened a second time " in our memory " (nostra memoria) in the consulship of Va- lerius Asiaticus [a. d. 46]. (Comp. Qa. Nat. vi.21.) According to the preceding statements there would have been live different eruptions of islands in the space of little more than 200 years. First Thera and Therasia themselves appeared in b. c. 237, ac- cording to Pliny; secondly Hiera, according to Euse- bius, Justin, Strabo, and Plutarch, in b. c. 197; thirdly Hiera or Automate, according to Pliny, 130 years later than the first occurrence, consequently in b. c. 107; fourthly, according to Pliny, 110 years afterwards, Thia, that is in a. d. 3; fifthly, according to Seneca and other writers, who will bo mentioned presently, an island in the reign of the emperor Claudius, A. d. 46. Now it is evident that there is some gross error in the text of Pliny, or that he has made use of his authorities with a carelessness which is not unusual with him. The most surprising thing is, that he has omitted the eruptions of the islands in B.C. 197 and a.d. 46, which are guaranteed by several au- thorities. His statement that Thera and Therasia first appeared in the 4th year of the 1 35th Olympiad,
