Lake Otero, X. Mcx. — Hcrrick. 189 
for refining- will be available and it 's only a matter of 
time when salt, soda and borax works will be erected. 
It is not impossible that fresh water could be found by 
deep drilling and a partial artesian head would probably 
be found. Jn this event the exploitation of the district will 
be facilitated. If one or more of the extensive irrigation 
schemes now on foot are carried to a successful completion still 
greater impetus will be given to manu<^ncturing enterprises in 
this valley. 
In conclusion I have to thank Mr. A. J. Hunt and my 
son, Mr. H. N. Herrick, for assistance in the work covered 
by the present paper. The chemical work involved was all 
done by the latter. I also am indebted for sundry suggestions 
to Dr. W. G. Tight of the Universit-; of Xew Mexico. 
EDITORIAL COMMENT. 
THE COLOSSAL BRIDGES OF UTAH. 
Mr. W. \\'. Dyar describes and illustrates in the Century 
Magazine for August, another great American wonder. Time 
was when the natural bridge of Virginia was held to be worthy 
of a long journey. It is rare indeed that the erosive forces are 
so balanced against the varying endurance of natural rock cliflfs 
as to excavate and undermine and leave intact a span of the 
firmer rock arching over an eroded softer stratum. Rare as this 
may be it is certainly rarer that arches as majestic as those de- 
scribed by Mr. Dyar should be wrought and preserved through 
the vicissitudes of Pleistocene time and remain to the present — 
indeed it is certain that no natural bridges equal to these are 
known in any part of the world. The unexplored interior of 
Africa may disclose natural arches of equal hight and span, but 
until such are discovered those of Utah will ven; easily rank 
first and will challenge the admiration of American travellers. 
These bridges are near the head of \\'hitc canyon in San 
Juan county. "Their walls and buttresses arc composed of 
pinkish sandstone, streaked here and there with green and or- 
ange-colored moss or lichens." The Caroline bridge, by a se- 
ries of rough triangulations was found to measure two hundred 
