438 Scientific Intelligence. 
ed on a smaller scale in the valley of the Tulare Lakes, into which the 
waters of the San Joaquin are said to ow when the river is high. 
The Gulf of California has undoubtedly extended far to the North 
of its present limits. Indeed the great ocean once washed the base of 
the Sierra Nevada and hid the interior of the country far from the 
light of day. In the slow, but persistent elevation of the continent 
since the tertiary era, the waters must have necessarily occupied more 
and more narrow limits, retiring from the elevated plain to the deep 
valleys until we find them imprisoned between the mountains of the 
Peninsula and the shores of Sonora. We cannot say that this elevatory 
movement has yet ceased; it is more probable that it still continues, 
although unappreciable during the comparatively momentary existence 
of man. ‘The lake may have been originally cut off from the upper 
part of the gulf by submarine elevation ; but, as the waters covered the 
whole surface, the sands could not have been acted on or drified by 
the northwest winds to form the gapposed barrier, as is suggested by 
your informant. 
4. Quicksilver Mine of Almaden, California; by W. P. Buake, 
(from a letter to J. D. Dana, dated San Francisco, Feb. 14, 1854.)— 
I visited the Quicksilver mine at New Almaden a few days ago, and 
took a general view of it, and the establishment for the reduction of 
the ore. { shall soon visit it again and spend several weeks for the pur- 
pose of making a full examination of the geology of the vein. 
The * Valley of San José’ is properly the southern end of the great 
valley occupied by the Bay of San Francisco. The ground slopes so 
gently towards the bay that it is hardly perceptible, and appears like a 
perfectly level plain ; the portion bordering the water is low and marshy, 
t 
The works (or “* Hacienda”) where the Cinnabar is reduced are two 
or three miles from the broad valley, up one of the small side val- 
leys of the mountains. The small village has the name of New Alma- 
den, and it has few inhabitants that are not employed in or about the 
works or the mine. , 
The mine is about one mile from the works, and high up on the side 
of the mountain. The cinnabar is brought down on mules that carry 
about lbs. each, and make two trips a ay. ae : 
‘ I expected to find the ore in close relation with the deposit of ni 
tary age, and among bituminous shales, but in this I was disappo!n'ee- 
All the tertiary beds appear to have been washed away, and hard seT- 
pentine and trappean rocks constitute a large part of the ridge in ah 
the ore is found. There are however large outcrops of sedimentary 
rocks, composed of alternating beds of argillaceous shales and 
Se 2 ES aie 
