DAVIS: THE GRAND CANYON OF THE COLORADO. 187 
them without difficulty ; but when actually upon them, the smoothness 
vanishes; the dimensions of every item of form are magnified far beyond 
expectation ; everything is rough and rugged, and walking is tiresome 
work. A third day can be given to various problems regarding stratified 
structures which are here open to observation in a larger way than almost 
anywhere else in the world. The mere sight-seer may be content with a 
brief trip down and back, but the geologist who can go as far as the 
canyon ought to spend several entire days in its depths. We were 
unfortunately so hurried as to have only an afternoon, a night, and a 
morning for the canyon. 
If the canyon is visited from the north, the trip may be made on 
horseback or with wagon from Belknap station, Rio Grande Western rail- 
road, southward to Kanab, and thence either southeast to the Kaibab 
or southwest to the Uinkaret plateau and the Toroweap valley. The 
former trip repeats the views seen from the Coconino rim, but it is 
without the advantage of good trails by which the descent may be made 
to the river. The latter takes the observer to a great field of volcanic 
phenomena as well as to the brink of the canyon at a most interesting 
point. After recent rains, water-pockets can be depended on for camp- 
ing near Vulcan’s throne; but if the season has been dry, water must 
be brought from Oak spring on the Uinkaret. Although this is trouble- 
some, it is entirely feasible. Two nights and a day are the shortest 
time that should be wisely allowed to this wonderful spot : it was a real 
hardship that our party had only a day for the ride from Oak spring to 
Vulcan’s throne and back. 
Former Climates of the Grand Canyon District. 
Diverse Opinions oF Earty OpseRvERS. — The several opinions ex- 
pressed by Newberry, Powell, and Dutton as to the former climates of 
the region under discussion seem to me difficult to maintain, so many 
are the doubtful elements in problems of this class. Newberry inferred 
a former greater rainfall (p. 47), apparently because of the immense 
amount of denudation that has been accomplished; but until more is 
known as to the time occupied in the great denudation, it is impossible 
to make inferences as to its rate, and hence as to the strength of the 
eroding and transporting agencies, and the rainfall that excites them. 
Powell inferred a long-maintained arid climate, because “in a region of 
country where there is a greater amount of rainfall, the tendency is to 
produce hills and mountains, rather than plateaus and ridges, with 
