276 TRANSACTIONS OF THE 



THE NORTHERLY WINDS OF CALIFORNIA. 



By J. H. C. Bonte, Secretary of the University of California. 



A frank and fair discussion of the northerly winds of California is much 

 needed. The first necessary step in this investigation is a correct knowl- 

 edge of the topography of the valley in which these winds prevail. 



TOPOGRAPHY. 



The great central, valley of California, known under the names of Sac- 

 ramento and San Joaquin, heads at Redding in the north, and extends to 

 Tehachapi Pass, in the south — a distance of four hundred and fifty miles, 

 with an average width of about forty-five miles. 



The Sierra Nevada Range of mountains bound this valley on the east 

 with a continuous wall, which has an average elevation of about six thou- 

 sand feet, and an average width of about eighty miles. This range is well 

 timbered from the foothills to the summit. It has a heavy Whiter snow- 

 fall, which remains on the highest points during the whole year, and feeds 

 the valley rivers during the Summer. There is no Summer rainfall on 

 this or any other mountain range in California. 



The valley is bounded on the west by the Coast Range mountains, a 

 range with but one gap — that at San Francisco — which is about half way 

 between the north and the south end of the valley. The average elevation 

 of this range is about two thousand five hundred feet, and its average 

 breadth about forty miles.- This range is poorly timbered on its eastern 

 slope, is rarely covered with snow, and then only for a very short time. 

 The winds of the Pacific Ocean pile up great fog banks on' the western 

 slope now and then, keeping the air on the ocean side moderately cool. 



These two ranges are united at the north end of the valley hy other 

 ranges, which are thus described by Rev. E. L. Greene: " There are sev- 

 eral mountain ranges in the north end of the State running in different 

 directions. The Siskiyou Range, which is largely in the State of Oregon, 

 runs mostly east and west, and averages about eight thousand feet in alti- 

 tude. From Mount Shasta, running in a northwesterly direction, is a high 

 range, separating Shasta Valley from the lava beds. Another high range 

 runs from the southwest base of Mount Shasta in a westerly direction. 

 Between these more conspicuous ranges are lower ranges, cutting up the 

 whole region in a succession of mountains and valleys. The mountains, 

 on their northwest slopes, are here and there densely timbered, at an eleva- 

 tion of three thousand and four thousand feet. Below three thousand feet, 

 the southward and eastward slopes are naked, or clothed only with chap- 

 arral. The country is not well watered: the rivers dry up in June. The 

 soil is in many places of volcanic origin. The lava beds contain some 

 small lakes; the larger Klamath lakes are on their borders. The eleva- 

 tion of the lava beds is over two thousand feet." 



George M. Gray, Chief Engineer of the Southern Pacific Railroad, 

 informs me that the Sierra Nevada Mountains and the Coast Range are 

 united at the south end of the valley by a continuous range of mountains 

 running east and west. This cross range, at Tehachapi Pass, reaches an 

 elevation of over four thousand feet. It is poorly timbered, and the sur- 



