THE VOLCANOES OF GUATEMALA. 
477 
and characterized by the emission of large quantities of fragmentary 
ejecta, ash, lapilli, and pumice, while often no lava is poured out. The 
last considerable eruption of Cerro Quemado was an exception, for not 
only were enormous quantities of lava discharged, but the form of the 
streams was peculiar. They consolidated on quite deep slopes, and often 
terminated in almost vertical walls, perhaps 100 feet or more in height. 
The lava appears to have been quite pasty at the time of its discharge, 
and to have quickly consolidated into a crust, which, as the lava under 
it continued to flow, broke up into blocks of varying but generally con¬ 
siderable size, and these have been pushed and rolled forward till they 
have formed a sort of wall, and have so helped to prevent the further 
progress of the lava. This, of course, is not unusual, but I have 
seldom seen the final slopes so steep, though another similar case 
occurs at Colima, in Mexico. As confirming the theory that the lava 
must have been pasty and almost consolidated at the time of its 
emission, I found in the crater of the mountain several well-marked 
bread-crust bombs, which are considered as characteristic of the Yul- 
canian type of eruption, i.e. where the explosions have taken place 
from among lava more or less consolidated. The idea is that the 
mass of lava before its ejection had cooled sufficiently for its surface 
to have consolidated, while the interior still remained pasty or even 
liquid, and that when it was thrown suddenly into the air, and the out¬ 
side pressure relieved, the vapours, which in different degree always 
exist in the lava, became separated and formed vesicles, and so swelled 
the mass and caused the crust to crack. One of these bread-crust 
bombs is shown in Plate I., and is indistinguishable from others I 
have seen on Yulcano, after the typical Yulcanian eruption of 1888, 
and also on Colima, where they appeared to be associated with the 
above-mentioned lava-stream. The crater itself presents confirma¬ 
tory appearances. It is a large hollow filled chiefly with blocks and 
slabs of well-consolidated lava with definitely broken edges, showing 
that they were quite solidified before they took their present position. 
It contains a few insignificant fumaroles, and some sparse pine trees are 
striving hard for a precarious existence. At the foot of the volcano are 
some hot springs at Almolonga, and at Zunil some small geysers. 
The volcano of Santa Maria, as viewed from the slopes of the Cerro 
Quemado, from which it is only a few miles distant on the south, appears 
as a very regular cone (Plate IT.). It is covered to the top on this, its 
north, side with vegetation, which appears to have been only partially 
destroyed by the great eruption of 1902. It was ascended in March, 
1902, only a few months before this eruption, by Mr. Walter S. Ascoli, 
who found a small crater on the summit, consisting of an irregular, 
shallow, rocky depression some 120 feet in diameter. At the bottom the 
rocks were split up, leaving narrow clefts between them, from which, 
however, no steam or vapour escaped. The beds forming the mountain 
