BY THE REV. J. E. TENISON-WOODS, F.G.S., &C. 729 



It would seem as if these volcanic disturbances at the bottom of 

 the lake must belong to some subaqueous crater. The locality of 

 them is in a prolongation of the line of fissure which extends 

 from Binintiang Munti through the main crater by Mt. Pinag 

 Ulbuan to these islands. From the repeated disturbance of this 

 part of the lake we may reasonably infer that this is one of the 

 main foci of volcanic activity, and is in fact a point corresponding 

 with what must have been the highest centre of the ancient and 

 submerged cratei-. The present crater is considerably to the west- 

 ward of this point, and probably is quite insignificant in com- 

 parison with the old volcanic vent. The excessive discharge 

 from this centre is probably the explanation of why it has sub- 

 sided the deepest. The fires may now be diverted entirely to 

 another channel, as so long a period has elapsed since there has 

 been any renewal of the disturbance in that direction. 



Fr-om 1731 there were 18 years of comparative quiet; but in 

 1749 there took place one of the most severe eruptions of which 

 there is any record since the arrival of the Spaniards in the 

 Philippines. At that date the parish priest of a neighbouring 

 town was Padre BencuchillOj " a man of observation and fond of 

 these kind of studies," who took care to witness as much as he 

 could of this eruption, and of the greater one in 1754, and wrote 

 a detailed account of what took place. 



At 11 o'clock at night, on the 11th of August, 1749, the first 

 indication of the eruption was a brilliant glow over the summit of 

 the volcano. This was followed at three in the morning by 

 continued detonations, which lasted until dawn. An immense 

 column of smoke began to I'oll forth from the cratei', with hundreds 

 of other little pillars from different parts of the island. From the 

 surface of the water of the lake there rose what the chronicler 

 describes in this and other places as perfect obelisks of sand and 

 mud, which, he states, reached certainly above the clouds, and then 

 spread out and fell back into the water. These jets, which came 

 forth from the depths of the lake, appeared in two principal 

 directions, one to the north and the other to the east of the volcano. 

 At nine in the morning violent earthquakes commenced, and as the 



