Central America consists of a high plain or table-land sloping gently towards the northeast, but terminating abruptly on the southwest. In the opinion of geologists this table-land consists of the surface of a huge tilted block of the earth's crust, or, perhaps, more probably, of a series of such blocks, that are limited on the southwest by a narrow belt of intersecting fractures. It is in these fractures that scores of volcanoes are situated, together with active craters, solfataras, and hot springs. The volcanoes are mainly of the Vesuvian type. There are so many volcanoes in this part of the world that it will be possible to describe but a few of them. We will begin with the volcano of Coseguina, situated on the Pacific coast of Nicaragua. Its appearance is that of a conical mountain with the top cut off, and suggests that it is most probably an explosive volcano which has had the top blown away during some of its great eruptions. Coseguina is celebrated by reason of its tremendous eruption of 1835. Before the still more tremendous explosive eruption of Krakatoa in 1883, described in the first two chapters of this book, Coseguina shared with Sombawa, on the island of Sumatra, as being the foremost of explosive volcanoes. It had been estimated that before its eruption of 1835, Coseguina had a height of perhaps 10,000 feet, but so much of it was blown away by this eruption that it now is a little less than 4,000 feet. The following description of the great eruption of Coseguina in 1835 has been condensed from an account prepared by Squier, published in 1850. You will note in reading this brief account how closely many of the phenomena resemble those that occurred during the eruption of Krakatoa in 1833. The eruption of Coseguina was heralded on the morning of January 20th, 1835, by several loud explosions that were heard for a distance of some 300 miles around the crater of the volcano. Then followed an ink black cloud formed directly over the mountain, which gradually spread on all sides shutting off the light of the sun, except for a sickly yellowish light. Fine sand was thrown from this cloud, which made it both difficult and painful to breathe. For two whole days the cloud continued to grow denser, the explosions louder and more frequent, and the rain of sand thicker. On the third day the explosions were strongest and the darkness greatest. The amount of sand that fell from the cloud was so great that people left their houses, fearing the roofs would be crushed in by the great weight. This sand fell in large quantities over an area more than 1,500 miles in diameter, or, quoting the language of Squier: