Page:Popular Science Monthly Volume 26.djvu/120

110 from below. A broad belt of white foam and towering breakers marks where the mighty waves, rolling shoreward in their might, with all the force gathered in an unbroken sweep of seven hundred miles across the Gulf, are suddenly arrested, and sink down, conquered and powerless, so soon as they come within the mysterious influence of this gentlest of rulers.

Unfortunately, this peaceful haven is very shallow; its depth is variously stated at twelve and eighteen feet, so that only vessels of light burden can here take shelter. But to these, blessed, indeed, is the change of passing suddenly from the wild tossing of the outer ocean to the wonderful calm of this strange harbor, where the weary crew may rest as securely as though within an encompassing coral reef. Indeed, the stranger approaching this wall of breakers would naturally assume it to be caused by a dangerous reef, and would, as a matter of course, seek safety by steering away from it.

We believe that no scientific examination of this so-called Oil-Spot has yet been made. Sailors who have here found refuge state that the bottom is of a soft, soapy mud, into which they can easily push a pole to a considerable depth—a mud which, when applied to deck-scrubbing, is found to be exceedingly cleansing.

That the existence of this little haven is due to a submarine oil-spring there can, we think, be little or no doubt, though we have no positive information of discovery of oil-springs on the seaboard of Louisiana or Texas. We know, however, there are many points around the Gulf where petroleum, asphalt, or naphtha in some form, is found in immense quantities, chiefly in the three eastern States of Mexico—Tamaulipas, Vera Cruz, and Tabasco. In the first of these, inexhaustible beds of asphaltum lie on both banks of the river Thames. It oozes in an almost pure state through the sedgy borders of the river, and is collected in boats of light draught, which convey it sixty miles down the stream to the port of Tampico.

In the State of Vera Cruz, asphaltum, naphtha, petroleum, stone-coal, and kindred bituminous substances, are found abundantly along the whole coast-range. Six counties are specified, one being especially rich in these deposits, which are sometimes found pure, sometimes mixed with rock-salt and saltpeter. Dr. Hechler, a scientific German traveler, has described the great asphalt-beds near the village of Moloacan. "The salt-mine," as it is there called, is an isolated conical mountain about twelve hundred feet in height, cracked by earthquakes. On its slopes are a number of pits, some of which are cold and still, others seething and bubbling with much noise and a stifling odor. Some of these seething pits eject masses of liquid asphaltum, which the Indians call chapopote. The whole adjacent surface consists of asphalt, partly liquid and partly solid, mingled with rock-salt. External heat and subterranean noises tell of the fires still smoldering within the mountain. Dr. Hechler hazards a suggestion that