342 J. D. Dana on the Volcanoes of the Moon. 
lumination of the craters. Well may the Vesuvian vulcanist look 
with doubt upon such vast gulfs; for he finds in his well known 
volcano, nothing parallel in kind or degree. The little dark hole 
at the top of his mountain, has scarcely a single monte of resem- 
blance to the open walled areas of the moon. 
- But the case is different with Kilauea, to which we now direct 
our attention. . We observe that the facts this crater Aen are 
pan the same in kind as those of the moon. 
. 1. The crater is a large open pit, exceeding three miles in its 
longer diaméter, and nearly a thousand feet deep. ; 
» 2 It has clear bluff walls through a greater part of its cireuit, 
with an inner ledge or poten at their base, raised 340 feet above 
the bottom. 
2 1Ehe totter da: plain of solid lavas, catincly open to ere 
which may be traversed with safety; over it there are pools of — 
boiling lava in active ebullition, and one is more than a thousand 
feet in diameter. There are also cones at times from a few yards 
to two or three thousand feet in diameter, and varying greatly in 
angle of inclination. The largest of these cones have a cpa 
pit or crater at summit. 
Compare these characters severally with the lunar craters, aud 
an identity will be perceived even to the ledge that surrounds 
lower pit, and the various forms of the cones. A large number 
of the lunar craters have an inner circle either as a terrace or ridge. 
The ledge within Timocharis (figure 1) is very similar to that of 
Kilauea, and is continued around the whole pit unbroken as im 
the Hawaiian crater. he other figures illustrate the same fea- 
ture in different conditions.. Some of them too contain circular 
areas with the rim scarcely elevated, (figure 2,) and others raised 
into cones, (figure 3): and so, in Si testeni there are at times boil 
ing lakes in the bottom plain, and other pools constitute the sum- 
mits of cones which they themselves have formed. 'T'o appre- 
ciate the comparison, it must be remembered that the Hawaiian 
pit-crater is upwards of three miles in length, and averages neat- 
ly half this in breadth ; and that the largest boiling pool, though 
more than a thousand feet in diameter, is still a small spot-in the 
extensive area. During times of greater activity, the whole pit 
is in every part lighted with the fiery lavas, overflowing at times 
ol Pe mamerous lakes, and sodanie from the many cones. 
