338 
PROFESSOR PHILLIPS ON SOME PARTS 
with many crater-formed mountains, occur also the Puy de Dome, Puy Sarcoui, Puy 
Chopin, and others which are heaps of a peculiar trachyte not excavated at the top, 
while the others are formed of ashes and lava-streams, and are all crateriform. The 
central masses of Theophilus (Plate XV.) are very, lofty and grandly fissured from the 
middle outwards, with long excurrent buttresses on one side, and many rival peaks 
separating deep hollows, and catching the light on their small apparently not excavated 
tops. This is like the upheaved volcanic region of Mont Dor, with its radiating valleys, 
wide in the central part, and contracted to gorges toward the outside of the district. 
The Yesuvian volcanic system, including the Phlegrsean fields, exhibits, in all respects 
but magnitude, remarkable analogy with parts of the moon studded with craters of 
various sizes, as those adjoining Mount Maurolycus, engraved for comparison by 
Mr. Scrope in his admirable treatise on Volcanos (p. 232). It is probable that many 
of the differences which appear on comparing lunar ring-mountains may be understood 
as the effects of long elapsed time, degrading some craters before others were set up, 
and turning regular cones and cavities into confused luminous mounds. It would much 
augment our confidence in the possible history of the moon which these differences seem 
to indicate, if we could believe it to have ever been under the influence of atmospheric 
vicissitudes as well as changes of interior pressure. 
That the latter cause has been in great activity at some early period of the moon’s 
history is evident, not only by the many sharply cut fissures which range like great 
faults in our earthly strata for five, ten, twenty, and sixty miles, but is conspicuously 
proved by the great broken ridges of mountains which, under the names of Alps, Apen- 
nines, and Riphaean chains, make themselves known as axes of upward movement, while 
so many of the craters near them speak of local depression. I have not been able to 
discover in these great ridges any such marks of successive stratification, or even such 
concatenation of the crests, as might suggest symmetrical and anticlinal axes. The 
surface is, indeed, as rough and irregularly broken as that of the Alps and Pyrenees, 
and marked by as extraordinary transverse rents, of which one, in the Alpine range near 
Plato, is a well-known example. Must we suppose these mountains to have undergone 
the same vicissitudes as the mountain-chains of our globe — great vertical displacement, 
many violent fractures, thousands of ages of rain and rivers, snow and glacial grinding 1 
If so, where are the channels of rivers, the long sweeps of the valleys, the deltas, the 
sandbanks, the strata caused by such enormous waste 1 If the broad grey tracts were 
once seas, as analogy may lead us to expect, and we are looking upon the dried beds, 
ought we not to expect some further mark of the former residence of water there than 
the long narrow undulations to which attention has already been called as resembling 
the escars of Ireland \ 
Among other curious phenomena probably referable to movement of the solid crust 
of the moon, are those long, straight, winding, or angularly bent fissures or cracks which 
the Germans call 4 Itillen.’ The distinctness of these cracks for such great lengths as 
some of them reach is consistent with extreme narrowness ; very narrow spaces, strongly 
