CLIMATE. 35 
latitude 39°, break through the Coast Mountains to reach the 
Pacific. It may be said that the waters of these streams, after 
their union, pass through three straits:\ one at the Golden 
Gate, one hundred feet deep and a mile wide; one at the 
.sraits of Carquinez, fifteen feet deep and three-quarters of a 
mile wide, thirty-five miles from the ocean; and one near the 
head of Suisun Bay, half a mile wide and ten feet deep. The 
Golden Gate and the straits of Carquinez afford an abundant 
outlet for all the water from the interior, but not so with the 
pass at the head of Suisun Bay. The land at this place is low 
—not more than six or eight feet above low-water mark—for 
a width of three miles, beyond which there are hills, which 
prevent the spreading of the water to a greater distance. The 
river is shallow and crooked; the banks lined with bushes and 
covered with tules, which obstruct the passage of the water in 
time of flood.. 
During the flood of January, 1862, there was very little 
perceptible increase in the height of the water in San Fran- 
cisco and Suisun Bays above the level of ordinary high tide. 
But there was no flow of the tide; a continual ebb of thick, 
muddy water, poured out at the Golden Gate for weeks to- 
gether, discoloring the sea to a distance of forty miles from 
iand. In the bays the water became almost fresh, and the 
planted oysters were killed by it in their beds near Oak- 
land. 
We may presume, since thirty-six inches of water fell at 
San Francisco from November to January inclusive, of 1861- 
62, that the same amount fell in all the low lands of the Sac- 
ramento Basin, nearly one-half of its area. We may presume 
further that the amount which fell at Sonora is a fair repre- 
sentation of the amount which fell on the Sierra Nevada, one- 
half of the area of the basin. But possibly snow, which has not 
yet melted, formed one-third of the snow and rain which fell 
on the Sierra Nevada. It is not, therefore, necessary to take 
any account of that third, in this consideration of the flood of 
1862—written, as it is, before the waters have gone down, 
