If you examine the map of Mexico on page 86 you will see that Jorullo lies 170 miles southwest of the city of Mexico, and 108 miles from the Pacific Ocean, which is the nearest large body of water. This mountain is of especial interest because, if old traditions are to be believed, it was thrown up during practically a single night. This wonderful event took place on an elevated plain or plateau, called the Plain of Malpais, that lies between 2,000 and 3,000 feet above the level of the ocean. The plain was situated in a part of Mexico that was celebrated for the growth of the finest cotton and indigo in the world. It formed the large estate of a wealthy planter, Señor Pedro de Jorullo, who lived at his ease as a wealthy planter is apt to do in tropical countries like Mexico. Jorullo's plantation was covered by an especially fertile soil, since it was formed by the deposits of volcanic ashes, dust, tufa, etc., produced, most probably, by neighboring volcanoes long before man appeared on the earth, for the plain of Malpais was bounded by hills that were composed of volcanic materials. There had, however, been no signs of volcanic activity in the neighborhood. It had indeed been quiet, so far as volcanic eruptions were concerned, since the time of the discovery of America by Columbus, until the middle of the last century. The fertile fields of the Jorullo plantation were watered by two rivers, or as we would probably call them, brooks, the Cuitamba and the San Pedro. Signs were not wanting of the coming calamity. During June, 1759, subterranean sounds were heard of a low rumbling character, which every now and then increased until they resembled in intensity the sounds produced by the firing of large guns. These sounds were accompanied by earthquake shocks that greatly terrified the people and caused them to flee from their homes. Nothing, however, occurred, so, becoming accustomed to the noises, the people returned to their houses. The noises and tremblings ceased for over two months, until, on the 29th of September, 1759, they were again heard, and a terrible eruption began. A long fissure opened in the earth, extending generally from northeast to southwest. From this fissure flames burst out, fragments of burning rock and stone, together with large quantities of ashes were thrown to great heights in the air, and were followed by streams of molten rock. Six volcanic cones were formed along the fissure. The highest of these cones is what now constitutes the volcanic mountain of Jorullo, which then reached a height of at least 1,600 feet above the level of the plain. From its cone were thrown out great quantities of lava of the same type as that which escaped from the craters of many volcanic islands such as Hawaii and Iceland, namely, basaltic lavas. This eruption, which began on the 29th of September, 1759, continued until the month of February, 1760.