248 



AUSTRALASIA. 



whose slopes occupy the whole space between the bays of San Miguel and Lagonoy, 

 terminating in a regular cone, 6,450 feet high. Ysarog has been quiescent through- 

 out modern times, and the only sign of former energy appears to be a spring of 

 carbonic acid near the summit. 



The northern part of the Camarines peninsula is dominated by the two volcanic 

 masses of Colasi and Labo (Tetas de Polantuna), which, however, have no craters, 

 and apparently have been at rest since prehistoric times. Majayjay (6,500 feet) 

 and San Cristobal (7,660 feet), south-east from JManilla, are also extinct. But west 

 of them stands the volcano of Taal, which, although only 780 feet high, is one of 

 the most remarkable in the Philippines. It occupies, with two other lesser cones, 



Fig. 108.— Central Part of Luzon. 

 Scale 1 : 2,500,000. 





hasC or ureenwich 



0to50 

 Fathoms. 



Depths. 



.50 to 100 

 Fathoms. 



100 Fathoms 

 and upwards. 



60 Miles. 



an islet in the middle of Lake Bombon, which is separated from the China 

 Sea by a low narrow isthmus. Taal, whose flanks are furrowed by deep gorges, 

 terminates in an enormous crater, out of all proportion with its size. "Purgatory," 

 as the natives call this crater, has a circumference of over 4,300 yards, and contains 

 in its depths secondary craters, numerous crevasses emitting vapours, and two blue 

 lakelets charged with sulphuric and hydrochloric acids in the proportion of over 

 six per cent. Formerly the two other volcanoes in the island — the Great and 

 Little Binintiang — ejected ashes alternately, and the bed of the lake itself was 

 occasionally in a state of eruption ; but since 1749 all the underground forces 

 have been centred in Mount Taal, which casts up showers of pulverised rock, but 



