Every one knows that the Philippine archipelago, like other regions in its neighborhood, abounds in volcanoes, some of which are still active, while the majority are extinct. Some geologists have tried to distribute the Philippine volcanoes into two parallel belts or lines running in a general northwest and southeast direction, following the trend of the island group, and extending from the southern end of Mindanao to the northern part of Luzon--some sixteen degrees of latitude. Early, possibly prehistoric, volcanic activity in the group has left its imprint upon the native mythology, as was the case in the Mediterranean, and an explanation of some of the mythical stories is to be found in earth movements. The Spaniards have given accounts of many eruptions in the last three hundred years, which were remarkable either from the destruction they caused or the terror they inspired. Some of these accounts were written by the terrified eyewitnesses themselves, such as the monks in charge of parishes where the greatest damage was done, and are sufficiently vivid, however much they may lack of what would now be called “scientific” accuracy. Probably the most remarkable volcanic outburst in historical times, on account of the distance apart of the simultaneous eruptions, although its intensity might not be regarded as great when compared with that of Krakatoa, was that of January 4, 1641, when a volcano on the southeastern extremity of Mindanao, another on the northern coast of the island of Sulu to the west, and a third in Luzon far to the north, became active at the same time. A translation of the original Spanish report of this extraordinary phenomenon, which is extremely rare and practically inaccessible to students, is given in Jagor’s _Reisen in den Philippinen_. From this it appears that upon two occasions, toward the end of December, 1640, volcanic ashes fell at Zamboanga (on the southwest coast of Mindanao) and covered the fields like a light frost. On January 1, 1641, the auxiliary fleet carrying troops from Manila to the island of Ternate was off Zamboanga, and on the 3d, at about 7 P. M., people in the latter place heard what they supposed was artillery and musketry firing at some miles’ distance. Believing that an enemy was attacking the coast, preparations were made to meet him, and the commander of the galleys sent a boat out to see if any of the vessels of the fleet needed assistance, but the boat returned without finding the fleet.