Reviews—Dutton’s Grand Canon, Colorado. 321 
amphitheatres, with outstanding remnants of the beds, of fantastic 
forms, yet perfectly intelligible upon considering the arrangement 
of the strata and the forces which have acted on them. It appears 
to us to be the appreciation of the fitness of means to the effect pro- 
duced, that in natural objects conveys the idea of beauty: and it is 
because it takes some while before the mind can embrace the con- 
nection of cause and effect under new conditions, that the scene, 
which bursts upon the view in the Canon, bewilders for a time, and 
then enchants with its beauty. In the view copied into Dr. Geilie’s 
Text Book, the spectator stands on the edge of the floor of the upper 
valley, called ‘The Esplanade,” and looks down into the inner chasm. 
To the right and left of the picture are seen the walls of the upper 
valley, not any of those cliffs which, as escarpments, terminate the 
various formations of the plateau country. All the rocks in this 
view belong to the Carboniferous. 
The fifth chapter, on the Toroweap Valley, describes some ex- 
tremely interesting facts about the vulcanism of the district. ‘There 
is also, as one of the illustrations of this chapter, a charming helio- 
type of the inner gorge of the Colorado at the lower end of that 
valley. But, above all, the section of basaltic dykes given in the 
diagram at p. 96 is to our mind one of the most valuable contribu- 
tions to geological knowledge in the entire work. Here we have, 
seen in a section half a mile deep, four dykes of basalt. Three of 
them have had their upper parts and whatever they may have ended 
in, cut away by the corrosion of the river. But the northern one 
terminates in a cinder cone, standing now at an extreme corner of 
the edge of the ‘“‘esplanade.” It is partly dissected away by the 
recession of the cliff on which it stands, so that its structure is 
exposed to view. It is most interesting to see the connection here 
between most ordinary looking basaltic dykes and an actual cone 
of eruption. 
It has just been announced that Captain niean has now under- 
taken the exploration of the great volcanic region of the Cascade 
Range. The work now before us gives assurance that the examina- 
tion of this fresh district will be thorough, and the report upon it 
highly instructive. If, however, we may be allowed to make a 
suggestion, it would be, that the scientific matter should be thrown 
together into a separate part, somewhat after the manner of Part IT. 
of Powell’s « Exploration of the Colorado River.” The geological 
reader of the present work feels somewhat oppressed with a little 
too much of what is no doubt very interesting and graphic, but yet not 
quite the strong meat in which he most delights. At the same time 
he does not dare to skip, for fear of missing some important fact or 
deduction, dropped by the way in the midst of somewhat effuse word 
painting. The book gives the impression of being written for two 
classes at once, and we cannot help thinking that it might have been 
arranged so that the perusal of some part of the descriptions of 
scenery might have been left optional to the scientific student, to 
whose eye the excellent illustrations at once convey nearly all the 
information of this kind which he requires. We may also remark 
DECADE II.—VOL. X.—NO, VII. Al 
