452 WALLACE E. PRATT 



spheroidal and ellipsoidal inclusions were found which are indis- 

 tinguishable from the mud balls of the last eruption of Taal. 

 These ejecta may have come from Taal itself, or from some other 

 of the numerous small craters which are known to have existed 

 in southwestern Luzon formerly. The wells were drilled by the 

 Bureau of Public Works with standard drilling rigs, and the samples 







•- 



l Z 1 



Centimeters » 



Fig. 2. — Photograph of balls of dried mud which fell with the fine tuff portion 

 of the ejecta of Taal Volcano, in the eruption of 191 1. 



studied were submitted by the drillers. The balls of dried mud 

 came from depths of from 100 to 150 meters in very loosely con- 

 solidated, silt-like volcanic tuff, fragments of which had evidently 

 caved into the well and had been brought to the surface by the 

 sand pump or bailer. Some of the balls were broken, but many 

 were intact in spite of the disintegrating effect which the rushing 

 action of the water into the bailer must have caused. 



The size and appearance of the balls are well shown in the 

 accompanying photograph (Fig. 2). One specimen still imbedded 



