Buenaventura, at a distance equal to that of Berlin from Basle, the Pyrenees from Fontainebleau, or London from Aberdeen. Although, since the commencement of the present century, the volcanoes of Mexico, New Granada, Quito, Bolivia, and Chili have been visited by some geognosists, the Sangay, which exceeds the Tungurahua in elevation, has unfortunately remained entirely neglected, in consequence of its solitary position, at a distance from all roads of communication. It was only in December 1849 that an adventurous and highly informed traveller, Sebastian Wisse, after a sojourn of five years on the chain of the Andes, ascended it, and nearly reached the extreme summit of the snow-covered, precipitous cone. He not only made an accurate chronometric determination of the wonderful frequency of the eruptions, but also investigated the nature of the trachyte which, confined to such a limited space, breaks through the gneiss. As has al eady been remarked, 267 eruptions were counted in one hour, each lasting on an average 13′′.4, and, which is very remarkable, unaccompanied by any concussion perceptible on the ashy cone. The erupted matter, enveloped in much smoke, sometimes of a gray and sometimes of an orange colour, is principally a mixture of black ashes and rapilli, but it also consists partly of cinders, which rise perpendicularly, are of a globular form and a diameter of 15 or 16 inches. In one of the more violent eruptions, however, Wisse counted only 50 or 60 red hot stones as being simultaneously thrown out. They usually fall back again into the crater, but sometimes they cover its upper margin, or visible by their luminosity at a distance, glide down at night, upon a portion of the cone, which, when seen from a great way off, probably gave origin to the erroneous notion of La Condamine, "that there was an effusion of burning sulphur and bitumen." The stones rise singly one after the other, so that some of them are falling down, whilst others have only just left the crater. By an exact determination of time, the visible space of falling (calculated therefore to the margin of the crater) was ascertained to be on the average only 786 feet. On Etna, according to the measurements of Sartorius von Waltershausen and the astronomer D. Christian Peters, the ejected stones attain an elevation of as much as 2665 60 Cosmos, see page 182.

feet above the walls of the crater. Gemellaro's estmates during the eruption of Etna in 1832, gave even three times this elevation! The black, erupted ashes form layers of three or four hundred feet in thickness upon the declivities of the Sangay for a circle of nearly fourteen miles in circumference. The colour of the ashes and rapilli gives the upper part of the cone a fearfully stern character. We must here again call attention to the colossal size of this volcano, which is six times greater than that of Stromboli, as this consideration is strongly in opposition to the absolute belief that the lower volcanoes always have the most frequent eruptions.

The grouping of volcanoes is of more importance than their form and elevation, because it relates to the great geological phenomenon of upheaval upon fissures. These groups, whether according to Leopold von Buch, they rise in lines, or united around a central volcano, indicate the parts of the crust of the earth, where the eruption of the fused interior has found the least resistance, in consequence either of the reduced thickness of the rocky strata, of their naturai structure, or of their having been originally fissured. Three degrees of latitude are occupied by the space in which the volcanic energy is formidably manifested in Etna, in the Æolian Islands, in Vesuvius, and the parched land (the Phlegræan Fields) from Puteoli (Dicæarchia) to Cumæ, and as far as the fire-vomiting Epopeus on Ischia, the Tyrrhenian island of Apes, Ænaria. Such a connexion of analogous phenomena could not escape the notice of the Greeks. Strabo says, "The whole sea commencing from Cuma as far as Sicily is penetrated by fire, and has in its depths certain conduits communicating with each other and with the continent. In such a

66

61 See Strabo, lib. v, p. 248, Casaubon :-exei koiλíaç rivás; and lib. vi, p. 276. Upon a double mode of production of islands the geographer of Amasia expresses himself (vi, p. 258) with much geological acumen. "Some islands," says he (and he names them), are fragments of the mainland; others have proceeded from the sea, as still happens. For the islands of the high sea (those which lie far out in the sea) were probably upheaved from the depths; whilst, on the contrary, it is more reasonable to consider those situated at promontories and separated by a strait, as torn from the mainland." The small group of the Pithecusæ consists of Ischia, originally called Ænaria, and Procida (Prochyta). The reason why this group was considered to be an ancient habitation of apes, why the Greeks and the Italian Tyrrhenians, conse

(combustible) nature, as all describe it, appear, not only Etna, but also the districts around Dicæarchia and Naples, and around Baie and Pithecusa ;" and from this arose the fable that Typhon lay under Sicily, and that, when he turned himself, flames and water burst forth, nay sometimes even small islands with boiling water. "Frequently between Strongyle and Lipara (in this wide district) flames have been seen bursting forth at the surface of the sea, the fire opening itself a passage out of the cavities in the depths and pressing upwards with force." According to Pindar the body of Typhon is of quently Etruscans, gave it such a name (apes were called appot, in the Tyrrhenian; Strabo, lib. xiii, p. 626) remains very obscure, and is perhaps connected with the myth, according to which the old inhabitants were transformed into apes by Jupiter. The name of the apes, apipoi, might relate to Arima or Arimer of Homer (Iliad, ii, 783) and Hesiod (Theog. v. 301). The words tv 'Apipois of Homer, are contracted into one word in some codices, and in this contracted form we find the name in the Roman writers (Virgil, Eneid, ix, 716; Ovid, Metamorph. xiv, 88). Pliny (Hist. Nat. iii, 5) even says decidedly:Enaria, Homero Inarime dicta, Græcis Pithecusa."

The Homeric country of the Arimer, Typhon's resting-place, was sought, even in ancient times in Cilicia, Mysia, Lydia, in the volcanic Pithecuse, at the crater Puteolanus, and in the Phrygian Phlegræa, beneath which Typhon once lay, and even in the Katakekaumene. That apes should have lived within historical times upon Ischia, at such a distance from the African coast is the more improbable, because, as I have already observed elsewhere, the ancient presence of the apes upon the Rock of Gibraltar does not appear to be proved, since Edrisi (in the 12th century) and other Arabian geographers, who describe the Straits of Hercules in such detail, do not mention them. Pliny also denies the apes of Ænaria, but derives the name of the Pithecusæ in a most improbable manner from Tilos, dolium (a figlinis doliorum). "It appears to me," says Böckh, "to be the main point in this investigation, that Inarima is a name of the Pithecusæ produced by learned interpretation and fiction, just as Corcyra became Scheria; and that Eneas was probably only connected with the Pithecusæ (Æneæ insula) by the Romans, who find their progenitors everywhere in these regions. Nævius also testifies to their connection with Æneas in the first book of the Punic War."

62 Pind. Pyth. i, 31. See Strabo, v, pp. 245 and 248, and xiii, p. 627. We have already observed (Cosmos, vol. v, p. 208), that Typhon fled from the Caucasus to Lower Italy, as though the myth would indicate that the volcanic eruptions in the latter country were of less antiquity than those upon the Caucasian Isthmus. The consideration of mythical views in popular belief cannot be separated either from the geography or the history of volcanoes. The two often reciprocally illustrate each other. That which was regarded upon the

such extent that "Sicily and the sea-girt heights above Cuma (called Phlegra, or the burnt field,) lie upon the shaggy breast of the monster."

Thus Typhon (the raging Enceladus) was, in the popular fancy of the Greeks, the mythical symbol of the unknown cause of volcanic phenomena lying deep in the interior of the earth. By the position and the space which he occupied were indicated the limitation and the co-operation of particular volcanic systems. In the fanciful geological picture of the interior of the earth, in the great contemplation of the surface of the earth as the mightiest of moving forces (Aristotle, Meteorol. ii, 8, 3), the wind, the inclosed pneuma, was recognised as the universal cause of vulcanicity (of fire-vomiting mountains and earthquakes). Aristotle's contemplation of nature was founded upon the mutual action of the external and the internal subterranean air, upon a theory of transpiration, upon differences of heat and cold, moisture and dryness (Aristotle, Meteor. ii, 8, 1, 25, 31, and ii, 9, 2). The greater the mass of the wind inclosed "in subterranean and submarine passages," and the more it is obstructed in its natural, essential property of moving far and quickly, the more violent are the eruptions. "Vis fera ventorum, cæcis inclusa cavernis" (Ovid, Metamorph. xv, 299). Between the wind and the fire there is a peculiar relation. (Tò τуρ ὅταν μετὰ πνεύματος ᾖ, γίνεται φλὸξ καὶ φέρεται ταχέως ; Aristotle, Meteorol. ii, 8, 3.—καὶ γὰρ τὸ πῦρ οἷον πνεύματός τις φύσις; Theophrastus, De Igne, § 30, p. 715). The wind (pneuma) suddenly set free from the clouds, sends the consuming and widely luminous lightning fash (πρηστήρ). "In the Phlegræa, the Katakekaumene of Lydia," says Strabo (lib. xiii, p. 628), "three chasms, fully forty stadia from each other, are still shown, which are called the windbags; above them lie rough hills, which are probably piled up by the red-hot masses blown up." He had already stated (lib. i, p. 57) "that between the Cyclades (Thera and Therasia) flames of fire burst forth from the sea for four days together, so that the whole sea boiled and burnt; and an island composed of calcined masses was gradually raised as if by a lever." All these well described phenomena are ascribed to the compressed wind, acting like elastic vapours. Ancient physical science troubled itself but little about the peculiar essentials of material bodies; it was dynamic, and depended on the measure of the moving force. We find the opinion that the increasing heat of the planet with the depth is the cause of volcanoes and earthquakes, first expressed towards the close of the third century by a Christian bishop in Africa under Diocletian (Cosmos, vol. v, p. 196). The Pyriphlegethon of Plato, as a stream of fire circulating in the interior of the earth, nourishes all lava-giving volcanoes, as we have already mentioned in the text. In the earliest presentiments of humanity, in a narrow circle of ideas, lie the germs of that which we now think we may explain under the form of other symbols.

universe which Plato establishes in the Phædo (p. 112114) this co-operation is still more boldly extended to all volcanic systems. The lava-streams derive their materials from the Pyriphlegethon, which "after it has repeatedly rolled around beneath the earth," pours itself into Tartarus. Plato says expressly that the fire-vomiting mountains, wherever such occur upon the earth, blow upwards small portions from the Pyriphlegethon (“ οὗτος δ ̓ ἐστὶν ὅν ἐπονομάζουσι Πυριφλεγέθοντα, οὗ καὶ οἱ ρύακες ἀποσπάσματα αναφυσῶσιν, önη av TúXWσi Tŷs yŷs"). This expression (p. 113 B.) of the expulsion with violence refers to a certain extent to the moving force of the previously enclosed wind, then suddenly breaking through, upon which the Stagirite afterwards, in the Meteorology, founded his entire theory of vulcanicity.

According to these ancient views the linear arrangement of volcanoes is more distinctly characterized in the consideration of the entire body of the earth, than their grouping around a central volcano. The serial arrangement is most remarkable in those places where it depends upon the situation and extension of fissures, which, usually parallel to each other, pass through great tracts of country in a linear direction (like Cordilleras). Thus, to mention only the most important series of closely approximated volcanoes, we find in the new continent those of Central America, with their appendages in Mexico; those of New Granada and Quito, of Peru, Bolivia, and Chili; in the old continent the Sunda Islands (the Indian Archipelago, especially Java), the peninsula of Kamtschatka and its continuation in the Kurile Islands, and the Aleutian Islands, which bound the nearly closed Behring's Sea on the south. We shall dwell upon some of the principal groups; individual details, by being brought together, lead us to the causes of phenomena.

The linear volcanoes of Central America, according to the older denominations the volcanoes of Costa Rica, Nicaragua, San Salvador, and Guatemala, extend from the volcano Turrialva near Cartago to the volcano of Soconusco, over six degrees of latitude, between 10° 9 and 16° 2, in a líne the general direction of which is from S.E. to N.W., aud which, with the few curvatures which it undergoes, has a length of 540 geog. miles. This length is about equal to the distance from Vesuvius to Prague. The most closely ap