Reviews—Dutton’s Grand Canon, Colorado. 319 
they are true to nature. These illustrations are the work of Mr. 
Holmes. 
The style of the book is almost as unique as the subject-matter. 
We seem rather to be reading the production of an enthusiastic 
artist skilled in geology, than of the emissary of a government office, 
commissioned with a toilsome and difficult survey. Nevertheless, 
nothing is left untold or undiscussed which comes within the com- 
pass of the task which he has undertaken. In some of the chapters 
he describes imaginary journeys; and it is at the moment of supreme 
interest during one of these, that he introduces his readers to the 
first sight of the Grand Cajon of the Colorado. “For eight miles 
from the Milk Spring we continue to cross hills and valleys, then 
follow a low swale shaded by giant pines with trunks three to four 
feet in thickness. The banks are a parterre of flowers. On yonder 
hill-side, beneath one of these kingly trees, is a spot which seems to 
elow with an unwonted wealth of floral beauty. It is scarcely a 
‘ hundred yards distant ; let us pluck a bouquet from it. We ride up 
the slope. 
“The earth suddenly sinks at our feet to illimitable depths. In 
an instant, in the twinkling of an eye, the awful scene is before us. 
Wherever we search the Grand Cation in the Kaibab, it bursts upon 
the vision in a moment.” 
The main purpose of the work is to describe the region on the 
northern side of that part of the Caiion which is called “ the Grand 
Canon,” and to give its geological structure and history. There is 
nothing of petrology or paleontology in the book. It is chiefly 
concerned with the stratigraphy of the district, and with the mode 
of evolution of the peculiar contours of the surface, as affected by 
the stratification and the climate, under the action of forces of 
erosion. There are, besides, extremely interesting discussions on the 
volcanic phenomena, which appear to have been continuous during 
late geological periods, and have apparently lasted into recent times 
over certain areas within the district. The relation of these out- 
bursts to the movements of faulting, plication, and change of level, 
are peculiarly interesting. 
The geological map included in the volume is the central portion 
cut out from the general map of the western part of the Plateau 
Province contained in the atlas. It comprises about two and a half 
degrees of latitude, from 294° to 82° N., and four of longitude, from 
110° to 114° W. The structure of the region is simple, while the 
scale of the phenomena is immense. We find a series of formations, 
from the Tertiary to the Carboniferous inclusive, nearly conformable 
with one another, and dipping at a slight angle towards the north- 
east. The successive escarpments of these formations form ranges of 
cliffs. Some of them exceed 2000 feet in height, a height which we, 
who have not seen them, can scarcely realize. But the rocky cliff on 
which the Gemmi Pass is cut, is about 2000 feet above the village of 
Loesh, so that if we could conceive that cliff extending in perspec- 
tive until it was lost in the distance, those who know it might form 
a notion of the scale of the scenery. The country being nearly bare 
