DEPARTURE FROM TRINIDAD. 199 The interest of this impression was heightened at the period. to which I here advert; when Saint Domingo was the centre of great political agitations, and threatened to involve the other islands in one of those sanguinary struggles which reveal to man the ferocity of his nature. These threatened dangers were happily averted; the storm was appeased on the spot which gave it birth; and a free black population, far from troubling the peace of the neighbouring islands, has made some steps in the progress of civilization, and has promoted the establishment of good institutions. Porto Rico, Cuba, and Jamaica, with 370,000 whites and 885,000 men of colour, surround Hayti, where a population of 900,000 negros and mulattos have been emancipated by their own efforts. The negros, more inclined to cultivate alimentary plants than colonial productions, augment with a rapidity only surpassed by the increase of the population of the United States. CHAPTER XXX. Passage from Trinidad de Cuba to Rio Sinu.-Carthagena.—Air Volcanos of Turbaco.-Canal of Mahates. On the morning of the 17th of March, we came within sight of the most eastern island of the group of the Lesser Caymans. Comparing the reckoning with the chronometric longitude, I ascertained that the currents had borne us in seventeen hours twenty miles westward. The island is called by the English pilots Cayman-brack, and by the Spanish pilots, Cayman chico oriental. It forms a rocky wall, bare and steep towards the south and south-east. The north and north-west part is low, sandy, and scantily covered with vege-. tation. The rock is broken into narrow horizontal ledges. From its whiteness and its proximity to the island of Cuba, I supposed it to be of Jura limestone. We approached the eastern extremity of Cayman-brack within the distance of 400 toises. The neighbouring coast is not entirely free. from danger and breakers; yet the temperature of the sea had not sensibly diminished at its surface. The chronometer of Louis Berthoud gave me 82° 7′ 37' for the longi 200 ABUNDANCE OF TURTLES. tude of the eastern cape of Cayman-brack. The latitude reduced by the reckoning on the rhumbs of wind at the meridian observation, appeared to me to be 19° 40′ 50′′. As long as we were within sight of the rock of Caymanbrack, sea-turtles of extraordinary dimensions swam round our vessel. The abundance of these animals led Columbus to give the whole group of the Caymans the name of Peñascales de las Tortugas, (rocks of the turtles.) Our sailors would have thrown themselves into the water to catch some of these animals; but the numerous sharks that accompany them, rendered the attempt too perilous. The sharks fixed their jaws on great iron hooks which were flung to them; these hooks were very sharp and (for want of anzuelos encandenados*) they were tied to cords: the sharks were in this manner drawn up half the length of their bodies; and we were surprised to see that those which had their mouths wounded and bleeding continued to seize the bait over and over again during several hours. At the sight of these voracious fish, the sailors in a Spanish vessel always recollect the local fable of the coast of Venezuela, which describes the benediction of a bishop as having softened the habits of the sharks, which are everywhere else the dread of mariners. Do these wild sharks of the port of La Guayra specifically differ from those which are so formidable in the port of the Havannah? And do the former belong to the group of Emissoles with small sharp teeth, which Cuvier distinguishes from the Melandres, by the name of Musteli ? The wind freshened more and more from the south-east, as we advanced in the direction of Cape Negril and the *Fish-hooks with chains. "Vidimus quoque squales, quotiescunque, hamo icti, dimidia parte corporis e fluctibus extrahebantur, cito alvo stercus emittere haud absimile excrementis caninis. Commovebat intestina (ut arbitramur) subitus pavor." Although the form and number of teeth change with age, and the teeth appear successively in the shark genus, I doubt whether Don Antonio Ulloa be correct in stating that "the young sharks have two, and the old ones four rows of grinders." These, like many other sea-fish, are easily accustomed to live in fresh water, or in water slightly briny. It is observed that sharks (tiburones) abound of late in the Laguna of Maracaybo, whither they have been attracted by the dead bodies thrown into the water after the frequent battles between the Spanish royalists and the Columbian republicans. BANK OF LA VIBORA. 201 western extremity of the great bank of La Vibora. We were often forced to diverge from our course; and, on account of the extreme smallness of our vessel, we were almost constantly under water. On the 18th March, at noon, we found ourselves in latitude 18° 17′ 40′′, and in 81° 50′ longitude. The horizon, to the height of 50°, was covered with those reddish vapours so common within the tropics, and which never seem to affect the hygrometer at the surface of the globe. We passed fifty miles west of Cape Negril on the south, nearly at the point where several charts indicate an insulated flat, of which the position is similar to that of Sancho Pardo, opposite to Cape San Antonio de Cuba. We saw no change in the bottom. It appears that the rocky shoal at a depth of four fathoms, near Cape Negril, has no more existence than the rock (cascabel) itself, long believed to mark the western extremity of La Vibora (Pedro Bank, Portland Rock, or la Sola), marking the eastern extremity. On the 19th of March, at four in the afternoon, the muddy colour of the sea denoted that we had reached that part of the bank of La Vibora, where we no longer find fifteen, and indeed scarcely nine or ten, fathoms of water. Our chronometric longitude was 81° 3'; and our latitude probably below 17°. I was surprised that, at the noon observation, at 17° 7' of latitude, we yet perceived no change in the colour of the water. Spanish vessels going from Batabano or Trinidad de Cuba to Carthagena, usually pass over the bank of La Vibora, on its western side, at between fifteen and sixteen fathoms water. The dangers of the breakers begin only beyond the meridian 80° 45' west longitude. In passing along the bank on its southern limit, as pilots often do in proceeding from Cumana or other parts of the mainland, to the Great Cayman or Cape San Antonio, they need not ascend along the rocks, above 16° 47′ latitude. Fortunately the currents. run on the whole bank to S.W. Considering La Vibora not as a submerged land, but as a heaved-up part of the surface of the globe, which has not reached the level of the sea, we are struck at finding on this great submarine island, as on the neighbouring land of Jamaica and Cuba, the loftiest heights towards its eastern boundary. In that direction are situated Portland Rock, 202 CURRENTS. OF THE SHOAL. Pedro Keys, and South Key, all surrounded by dangerous breakers. The depth is six or eight fathoms; but, in advancing to the middle of the bank, along the line of the summit, first towards the west and then towards the northwest, the depth becomes successively ten, twelve, sixteen, and nineteen fathoms. When we survey on the map the proximity of the high lands of San Domingo, Cuba, and Jamaica, in the neighbourhood of the Windward Channel, the position of the island of Navaza, and the bank of Hormigas, between Capes Tiburon and Morant; when we trace that chain of successive breakers, from the Vibora, by Baxo Nuevo, Serranilla, and Quita Sueño, as far as the Mosquito Sound, we cannot but recognize in this system of islands and shoals, the almost-continued line of a heaved-up ridge, running from N.E. to S.W. This ridge, and the old dyke, which link, by the rock of Sancho Pardo, Cape San Antonio to the peninsula of Yucatan, divide the great sea of the West Indies into three partial basins, similar to those observed in the Mediterranean. The colour of the troubled waters on the shoal of La Vibora, has not a milky appearance like the waters in the Jardinillos, and on the bank of Bahama; but it is of a dirty grey colour. The striking differences of tint on the bank of Newfoundland, in the archipelago of the Bahama Islands and on La Vibora, the variable quantities of earthy matter suspended in the more or less troubled waters of the soundings, may all be the effects of the variable absorption of the rays of light, contributing to modify to a certain point the temperature of the sea. Where the shoals are 8° to 10° colder at their surface than the surrounding sea, it cannot be surprising that they should produce a local change of climate. A great mass of very cold water, as on the bank of Newfoundland, in the current of the Peruvian shore (between the port of Callao and Punta Pariña*), or in the African current near Cape Verd, have necessarily an influence on the atmosphere that covers the sea, and on * I found the surface of the Pacific ocean, in the month of October, 1802, on the coast of Truxillo, 15.8° cent.; in the port of Callao, in November, 15.5°; between the parallel of Callao and Punta Parina, in December, 19°; and progressively, when the current advanced towards the equator, and receded towards the W.N.W., 20.5° and 22.3°. the climate of the neighbouring land; but it is less easy to conceive that those slight changes of temperature (for instance, a centesimal degree on the bank of La Vibora), can impart a peculiar character to the atmosphere of the shoals. May not these submarine islands act upon the formation and accumulation of the vesicular vapours in some other way than by cooling the waters of the surface? Quitting the bank of La Vibora, we passed between the Baxo Nuevo, and the light-house of Camboy; and on the 22nd March, we passed more than thirty leagues to westward of El Roncador (The Snorer), a name which this shoal has received from the pilots, who assert, on the authority of ancient traditious, that a sound like snoring is heard from afar. If such a sound be really heard, it arises, no doubt, from a periodical issuing of air compressed by the waters in á rocky cavern. I have observed the same phenomenon on several coasts, for instance, on the promontories of Teneriffe, in the limestones of the Havannah,* and in the granite of Lower Peru, between Truxillo and Lima. A project was formed at the Canary Islands, for placing a machine at the issue of the compressed air, and allowing the sea to act as an impelling force. While the autumnal equinox * is everywhere dreaded in the sea of the West Indies (except on the coast of Cumana and Caracas), the spring equinox produces no effect on the tranquillity of those tropical regions: a phenomenon almost the inverse of that observable in high latitudes. Since we had quitted La Vibora, the weather had been remarkably fine; the colour of the sea was indigo-blue, and sometimes violet, owing to the quantity of medusæ and eggs of fish (purga de mar) which covered it. Its surface was gently agitated. The thermometer kept up, in the shade, from 26° to 27"; not a cloud arose on the horizon, although the wind was constantly north, or N.N.W. I know not whether to attribute to this wind, which cools the higher layers of the atmosphere, and there produces icy crystals, the halos which were formed round the moon two nights successively. The halos were of small dimensions, 45° diameter. I never had an opportunity of seeing and measuring anyt of which the diameter had at *Called by the Spanish sailors "El Cordonazo de San Francisco." + In Captain Parry's first voyage, halos were measured round the sun |