Geologists know well that on one of these lines of disturbance, such as has been described, molten and disintegrated material is apt to come to the surface as lava and ashes; they expect also to find metallic veins, especially of the precious metals, and hot springs with various minerals in solution, and they infer earthquakes. All these phenomena are present in Central America in full force. Immense cones have arisen along the Pacific slope since the general features of the land were made, and not only have spread vast deposits around their base, but have blocked up valleys, forming lakes as Atitlan, built promontories as Coseguina, islands as Ometepec in the Lake of Nicaragua, and have turned rivers, changed prevailing winds, and otherwise altered the physical conditions of the country. Gold sands from the disintegrated veins sparkle in every mountain-brook, and the deposits of silver are no doubt as rich as those of Mexico, Nevada, and Potosi. _Aguas calientes_, or hot springs, are found all over the country, and earthquakes, often severe, are common on the Pacific slopes. All along the Atlantic side the rock material is limestone or dolomite, while as one goes westward he meets andesyte and other forms of trachytic lava, such as pumice and obsidian. Even among the limestone mountains of the northeast are occasional volcanic deposits, exactly as might be expected when so extensive an upheaval has taken place. Whatever has been the exact process by which this essentially mountainous country has been formed, we have at present at its northern boundary the high plain of Anahuac, extending from Mexico (where it is interrupted by the Isthmus of Tehuantepec) through Guatemala; of somewhat lower level in Honduras and Salvador; sinking to almost sea-level in Nicaragua (154 feet); and rising again in the Altos of Veragua to about 3,250 feet. This main range has its axis much nearer the Pacific shore and almost parallel to it, being in San Salvador distant seventy-five miles, and in Guatemala (Totonicapan) only fifty. Towards the Pacific the slope is steep, interrupted by many volcanoes; while on the Atlantic side the gently terraced incline is broken into subsidiary ridges extending to the very shores. In the oceanic valleys and along the coast are the only lowlands of Central America; and these contain the wash of volcanoes, limestone mountains, and ages of vegetable growth and decay, forming the richest of soils for agricultural purposes.