MOJAVE VALLEY TO MOUTH OF BLACK CANON—DIFFICULT RAPIDS: 77 
The timbers fastened to the Explorer’s hull are a greater hindrance to her progress in this 
part of the river than below. They become wedged in the rocks, and render it difficult to 
extricate the boat, besides increasing the draught by the amount of their thickness, whieh’ is 
four or five inches. As has been the case at places in the lower portions of the Colorado, the 
bar that has here detained us three days would not have stopped a boat of six inches less 
draught, with a smooth bottom, as many hours. It is probable that there is not one season in 
ten when even the Explorer would encoubter one-fourth of the difficulty that she has during 
the present unprecedentedly low stage of water. 
= —= 
Fig. 20.—Deep Rapid. 
Treteba has become warmly interested in our hopes of reaching the Great Bend. He had 
thought that the Deep rapid would put a stop to the steamboating, and since that has’ been 
passed entertains a higher opinion of the capabilities of our craft. He told me this evening 
that there are yet four difficult rapids this side of the Great Bend; that the last of these 
occurs in an immense cafion, where the channel is filled with huge rocks, through which the 
water rushes in a furious torrent. Here, he informs me in emphatic pantomime, we shall come 
toa dead stop. Not far above, according to his account, the Colorado makes the bend to the 
east and a stream comes in, the water of which is salt. This, it would seem, must be the 
Virgen, for the upper waters of that river are known to have a brackish taste. a 
The late detentions have afforded Dr. Newberry and Mr. Hgloffstein excellent opportunities 
to pursue their respective avocations. The doctor has had leisure to make a very full and 
perfect mineralogical collection, and become thoroughly conversant with the geological char- 
acteristics of the region. Mr. Egloffstein has taken panoramic views of the river and the adjacent 
country, and has now completed a set that extends from Fort Yuma to the present camp. The 
