russell.] PARASITIC CONES. 81 
regular intervals of approximately 70 feet, although in some instances 
the bases of two adjacent cones touch each other. Each of these cones 
is of the nature of a chimney built about a small vent from which 
steam was issuing with considerable force and throwing out clots of 
plastic and even liquid lava. In most instances the chimney-like 
openings through which steam escaped have been closed by the falling 
in of the summit portions of their walls, but at the west end of the 
series there are two craters still complete and having vertical shafts 
in their interior. The openings referred to are nearly circular in 
horizontal sections and about 3.0 feet in diameter at the top and 50 to 
60 feet deep; midway down they contract, and expand again below, 
giving to them in vertical section an hour-glass form. In the smaller 
cone at the west end of the series the opening in its most constricted 
part is rudely elliptical, the principal axes measuring about 8 and 12 
feet. Its companion is somewhat larger and less regular. The walls 
above the constrictions midwa}^ down are nearly vertical and overhang 
their lower portions. On the sides there are adhering clots and splashes 
of lava which ran down before cooling and now occur in part as pendent, 
stalactite-like forms. When seen from above the walls appear smooth, 
bat on descending part way and looking up the irregularities due to 
the pendent clots become conspicuous. 
At the bottom of the smaller of the two openings there are two 
chambers or enlargements, looking like the mouths of tunnels, one to 
the northwest, one to the northeast. These openings are about 15 feet 
wide and 10 to 12 feet high. The other open shaft has but one 
expansion at the bottom similar in size to those just mentioned and 
leading toward the northeast. The enlargements in these two instances 
arc at about the same depth below the summits of the vertical shafts 
with which they communicate, but owing to the greater height of the 
pile of lava balls, etc., about one opening they are not at the same 
depth below the surface of the lava stream on which the cones stand. 
The chamber at the bottom of the smaller cone is about 20 or 30 feet 
below that at the bottom of its companion. At the bottom of the shaft 
in the smaller cone at the time of my visit (September 4, 1901) there 
was a conical mass of white ice, about 10 feet thick in its central part 
and about 15 feet in diameter at the base; adjacent to its northern side 
was a pool of clear water. The ice was exposed to the sky, but could 
not be reached b}^ the direct rays of the sun even in midsummer. 
Ice and water are also present at the bottom of the large shaft. 
These are about the simplest examples of " ice wells" that can be 
imagined. Clearly the ice is a remnant of the previous winter's snow, 
compacted by the freezing of percolating water. a 
"An instructive account of "ice caves," "ice wells," etc., may be found in a book by Edwin Swift 
Balch, entitled "Glacieres, or Freezing Caverns." Philadelphia, 1900. 
Bull. 199—02—6 
