THE VOLCANO IRAZU 



131 



daughter craters are of different depths; thus the floors of 

 J and A appeared to us higher than those of all the others, 

 while G and H seemed the deepest. 



North 



Eait 



SamraLt 



SoatK 



Sketch-Plan of the Craters of Irazu, April 2, 1910 



from point S on the edge of the rim where the 00 -shaped "daughter- 

 craters" meet. T, location of our tent on the floor of the " mother-crater," 

 10,880 feet above sea-level. 



I, "Mother-crater," II, Eastern "daughter-crater," III, Western 

 "daughter-crater," A-J, "granddaughter craters" in the larger, western 

 daughter-crater. 



Dotted line shows our route of April i, 1910. 



vr. Bare faces of vertical rock are exposed here. 



Ir, Laminated rock, the layers more or less horizontal. A piece of this 

 rock collected in April, 1910, was identified as tuff from a hardened mud- 

 flow of the volcanic ash Tprobably). 



Floor of mother-crater, especially in its eastern part near T of fine 

 black sand, and on this floor at least the yellow grass-like plant is chiefly 

 associated with fine sand. The western part of this floor consists of 

 coarser cinders interspersed with large and small boulders of angular 

 outline. A subcubical block about 3.5 centimeters on an edge, brought 



