HISTORICAL ERUPTIONS

There are several craters in Trinidad. S. of Cape Dela Brea is a submarine volcano, which occasionally boils up, and discharges a quantity of petroleum; in the E. part of the island and Bay of Mayaro is another, which, in March and June, gives several detonations resembling thunder,- these are succeeded by flames and smoke, and, some minutes after, pieces of bitumen, 88 black and brilliant as jet, are thrown on shore. Near the forests of point Icacos, on the summit of a hill of argillaceous clay, M. Levyasse found & great number of little mounds, about two feet high, whose truncated and open-coned tops exhaled a gas smelling like sulphurated hydrogen j one cone, of six feet high, on the most elevated part of the hill, continually discharged whitish matter, of an aluminous taste ; a sound was heard, indicating a fluid in a continual state of agitation, and globules of an elastic gas evaporated continually ; the scum at the top was cold j four poles, measuring sixty feet, did not touch bottom, and disappeared on being let go. There is neither stone nor sand within the circumference of a league of the cone ; but handsome rounded pebbles were found round the hill, together with small calcareous stones, encrusted with sulphur of a prismatic form. Contiguous to this crater, and encompassed, by a marsh of mangroves, which communicate with the sea, is another hillock, with a circular shallow cavity full of a boiling liquid like alum ; a dull subterraneous sound was heard, the earth was found to tremble under the feet of the explorers, and two poles pushed into the crater disappeared in an instant; detonations like distant cannon are heard every year in the month of March. It is remarkable that earthquakes, felt violently in the Antilles in 1797, were not perceived at Trinidad or in Cumana, and when the latter province was shortly after desolated by terrible earthquakes, the shocks were slightly felt in Trinidad, but not at all in the Antilles.

Forty miles S. of the Pitch Lake (vide Mineral Kingdom), are several mud volcanoes, in a plain not more than four feet above the general surface; the largest is about one hundred and fifty feet in diameter, and has boiling mud constantly bubbling, but never overflowing, remaining constantly within. the surface of the crater. When the old craters cease to act, new ones invariably appear in the vicinity ; thus resembling the mud volcanoes witnessed by Humboldt. Some of the mud volcanoes throw out salt water, heavily loaded with argillaceous earth :-during the hottest months of the dry season, cold mud is thrown to the height of thirty feet, and the volcano is unapproachable to within fifty paces. 'The following detailed description of this extraordinary phenomenon is worthy of perusal. 'They are situated near Point lcaque, the southern extremity of the island, on an alluvial tongue of land, that been appended to the primitive rocks, where, no doubt, the land originally terminated. This appendage is several miles in length, and points directly into one of the mouths of the Orinoco, on the main land, about twelve or fifteen miles off. 'We landed nearly opposite to where we were told we should find the mud volcanoes-and, after making our way about five miles across the sandy isthmus, we came upon two plantations, very pleasantly situated, amidst a group of remarkably round little hills, each from eighty to 100 feet in height. Our path, on leaving these, led us through some very thick wood of tall trees, till we found ourselves again upon a pretty .steep regular ascent, which had nothing remarkable in it ,except .the diminishing height of the trees as we went up. Only the tops of the trees, which were of the kind that usually grow near lagoons and salt marshes, at last appeared above .the ground, as we opened a perfectly uniform road bare platform of several acres, with different chimneys in the shape of truncated cones, the highest of them not exceeding three feet, some of which were throwing out, with a strong bubbling noise, salt water, about as salt as that of the Gulph of Paria, loaded, as much as it could be to preserve its fluidity, with argillaceous earth. In some of the chimneys this went on slowly or not at all-in others it might be called a pretty active cold ebullition. The surface of the platform round the chimneys was perfectly fine-and one of our party picked up a white sea shell of the turbinated kind, in the act of being thrown out along with the mud. e We afterwards procured various pyritic fragments that had been picked up in a similar manner-but the inhabitants of the quarter assured us that the ebullition, even during its greatest activity, was quite ,cold. The smooth circular platform was bounded by a perfectly regular parapet of clay, about three feet in height, propped up as it were by the tops of the trees, that like shrubs were shooting out of the ground immediately behind it. This appearance was most likely to be referred to the buried trees around having had time to shoot out in the interval between the two last great eruptions, which take place only during the hottest months of the dry seasons, and then the noise is described to be like the loudest cannon; the mud being thrown up to the height of at least thirty feet in the air, and the theatre of the eruption being unapproachable within fifty paces.  Close to the first volcano, but in a much more low and sunk situation, is another of precisely the same appearance and character, with only a narrow ravine between the two. e Such an extraordinary phenomenon induced us to examine the neighboring mounts of the cleared country, close to which stands tube residence of Monsieur Chancelier, a French planter -and we found them all (bating only the eruption) to possess the same form and composition, in all respects, as those we had just quitted. The platform and parapet were easily distinguishable, the chimnies only were gone; but just small pits were left in their places, filled with mud, from which air bubbles rose, even under our own observation; and our conductor, the intelligent manager of the estate, told us that when these rose in salt water, a fresh eruption was to be apprehended. He pointed out the former site of his master's residence, half up the mount, which had been destroyed by one of these eruptions, after & period of cessation so long that no record remained of the one that had preceded it; and he assured us that, during the period he had lived there. (fourteen years) the largest mount now in activity had gained a very considerable increase of height.

1911 ERUPTION