Notes on Upper California. 247 



Such trisection is not unfrequently desired in the geometrical 

 drawings and designs in various branches of engineering ; as for 

 instance in carpentry, in church architecture and in fortification 

 especially. For persons engaged in these branches, an instru- 

 ment like the one I have described will very likely afford some 

 interest 



Art. XXV. — Notes on Upper California; by James D. Dana.* 

 From Observations made during the Cruise of the United 

 States Exploring Expedition, under Capt. Charles Wilkes, 



U. S. N * 



The party with which the writer was associated on a tour from 

 Fort Vancouver to San Francisco, was under the command of 

 Lieut. G. F. Emmons, by order of Capt. Charles Wilkes. Our 

 route lay between the Cascade Range and the sea. 



On the 30th of September, 1841, we reached the Clammat (or 

 Tlamath), a fine river just south of the parallel of 42°, and en- 

 camped on a narrow plain not far from its banks, near the merid- 

 ian of 122f ° W. The lower elevations and the loftier hills 

 around consisted of tertiary sandstone, dipping at an angle of 20° ; 

 while the summits of the principal heights were composed of ba- 

 salt outcropping through the stratified rocks. The slopes were 

 strewed with chalcedony and agates, that had fallen from the 

 decomposing basalt, and the soil partook of the chocolate-brown 

 color, loose texture, and fertility, usual where this rock prevails. 

 Much of it was deeply cracked from drying during the long 

 drought. The sandstone resembled the tertiary rock of Astoria, 

 and was probably of the same age — the miocene. It was soft 

 and^friable, and of a grayish white color. 



The view from a neighboring eminence was a pleasing one. 

 An open prairie thinly covered with oaks, and bearing occasionally 

 a grove of pines, lay spread out among grassy hills and other 

 elevations bristled with evergreens. The Clammat seemed to 

 now along a narrow valley from the far east, and continued its 

 course among the hills that broke up the country to the west- 

 ward ; and a streamlet with a border of shrubbery meandered 

 over the plain towards the river. A rounded summit, exceeding 

 one thousand feet in height, stood to the south-southeast, and 

 shut from sight the snows of the Shasty Peak, a volcanic cone, 

 twelve to fourteen thousand feet high, which had been in view 

 from mountains just north of the Clammat. 



The Geology of the region here treated of is described with more systematic 

 detail in the Exploring Expedition Geological Report of the author, which is just 

 now printed excepting the Plates. It forni9 a volume of 760 pages in 4to, to be 

 illustrated by 3 maps, besides 21 plates of fossils in folio. 



■■ 



