GEOLOGY. val 
mantic sites, destined to become places of fashionable resort 
when our population grows dense. There are so many of 
these springs in the state that there is not room here to men- 
tion them all. 
In San Bernardino valley there are a number of warm 
springs. Their temperatures are thus reported: 108°, 128°, 
130°, 166°, 169°, and 172°. The heat of the springs at Aguas 
Calientes, in San Diego county, is thus given: 58°, 74°, 130°, 
136°, and 140°. 
Near Warner’s ranch, in San Diego, is a spring with a tem- 
perature of 135°, rising from a cleft in the granite rock. 
§ 51. Cortes Shoal— About one hundred miles west of San 
Diego is Cortes Shoal, twenty miles long and three miles 
wide, with a depth of only fifteen feet in one place. This 
shoal is evidently the summit of a submarine ridge of moun- 
tains, parallel with the other ridges of-the coast. The shoal 
was discovered in December, 1852, by Captain Cropper, of the 
steamship Cortes, who asserted that there was evidently a sub- 
marine volcano in operation there. The water was in violent 
commotion, and at intervals was thrown up into the air in col- 
umns; there was an escape of steam, and he suddenly found 
the depth of water change from forty-five to nine fathoms. 
He saw also light and smoke, and at one time the place looked 
as though it were a ship on fire. The general opinion is, that 
he saw only the waves breaking upon the Bishop Rocks, as the 
rocks at the shallowest place are called; but some persons ad- 
here to his opinion of a submarine volcano. 
Nots.—The chief writers upon the Geology of California are W. P. Blake, 
J. 8. Newberry, an.t Jules Marcou, in the United States Pacific Railroad Sur- 
vey reports, and Dr. J. B. Trask’s reports to the state legislature, and Jules 
Marcou’s book on the Geology of North America. For the chemical fineness 
of the gold in the various mining districts, I am indebted to Henry Van Valk- 
enburg. 
