ad 
ious points along the line of its axis for 2 or 3 miles, and a 
190 B. Silliman, Jr., on the New Almaden Quicksilver Mines. 
Arr, XVIIL.—WNotes on the New Almaden Quicksilver Mines; by 
. SILLIMAN, Jr. 
Tur New Almaden quicksilver mines are situated on a range 
of hills subordinate to the main coast-range, the highest point 
of which at the place is 1200 to 1500 feet above the valley of 
San José. Southwest of the range which contains the quick- 
silver mines, the coast-range attains a considerable elevation, 
Mt. Bache, its highest point, being over 8800 feet in height. 
elevation above the ocean. From San José to New Almaden 
the distance is 18 miles, with a gradual rise of 150 or perhaps 
200 feet. 
The rocks forming the subordinate range in which the quick- 
silver occurs, are chiefly magnesian schists, sometimes calcareous 
The workings are approached, however, by a well-graded wagon’ 
road, skirting the edges of the hills, which is 23 miles in length. 
hill was known for a long time prior to the discovery that 1 
any economic value. In fact, upon the very loftiest 
and could be obtained by a slight excavation or even by break- 
ing the rocks lying upon the surface. In looking about for 
one observes on the summit of the hill, at va- 
. 
