1914] Sumner, et al.: Physical Conditions in San Francisco Bay 19 
Since on these bottoms the instrument buried itself in the mud far 
beyond the upper valve, it is certain that much longer samples could 
have been taken had the length of the tube been greater. 
These various water and bottom samples taken during the field 
work were preserved for subsequent laboratory study on shore. The 
methods followed in the treatment of these will be discussed at length 
in a later section of this report. 
Some months after the preparation of the present report, it was 
found possible to test the Albatross sampler in comparatively deep 
water. The trial was made on April 6, 1914, about 13 miles southwest 
of Farallon Light, at a depth of 815 fathoms. The instrument was 
lowered twice, a bottom sample being taken in each case. The longer 
of these was nearly 3 feet (86 em.) long, the other being about 6 
inches shorter. 
III. DIMENSIONS, AREA, AND VOLUME OF 
SAN FRANCISCO BAY 
Those unfamiliar with the general geographical features of San 
Francisco Bay will find these indicated in plate 1. This bay extends 
in a direction roughly parallel to the coast line, i.e., from north-by- 
west to south-by-east, and lies between latitude 37° 25’ and 38° 10’ N. 
At a point considerably nearer the northern than the southern end 
it communicates with the Pacific Ocean through a strait, the Golden 
Gate, which has a minimum width of less than one nautical mile. 
Exact figures respecting the linear dimensions and area of this 
bay are difficult to give, since the limits of an irregular body of water, 
surrounded by marshes and prolonged into estuaries, must necessarily 
be chosen rather arbitrarily. Throughout the present paper the name 
“‘San Francisco Bay’’ will be applied to the entire sheet of water, 
extending from the mouth of Sonoma Creek at the extreme northern 
end to the mouth of the so-called ‘‘Coyote River’’ at the extreme 
southern. We ean find no valid reason, either geographic or hydro- 
eraphie, for treating San Pablo Bay as an independent body of water. 
As thus defined, San Francisco Bay has a length of about 45 
nautical miles, or 52 statute miles (83 kilometers), measured along a 
straight line between the points above mentioned. By water the dis- 
tance between these points would, of course, be considerably greater 
