1914] Sumner, et al.: Physical Conditions in San Francisco Bay 89 
B.—PRELIMINARY REPoRT Upon THE Bottom Derposits 
As stated in Part A, bottom samples were taken at all of the dredg- 
ing stations. They were likewise taken at most of the positions repre- 
sented by the hydrographic stations of the regular series.** At the 
dredging stations samples of the bottom material brought up by one 
or more of the appliances used were saved, notes being made regarding 
the consistency, color and texture of this material while fresh. These 
notes will be found in the records of the dredging stations, constituting 
Appendix I to the present report. That these preliminary character- 
izations of the various bottoms do not always agree with the results 
of the more careful subsequent examinations in the laboratory is 
probably due, in most cases, to the lack of uniformity in the mass of 
material brought in by the dredge. A deseription quite applicable 
to one part of the dredge-load would, in some eases, have been quite 
inadequate if another sample had been chosen. 
The bottom materials were preserved in various ways. Stones and 
gravel were simply dried and kept in bags. Mud and sand were 
placed in bottles or jars. It was our practice at the outset to retain 
two of these samples, one in alcohol, the other without any preserva- 
tive. Later, two alcoholic samples were bottled. One of these was 
intended for use in the study of the bottom material itself, the other 
for an examination of the organisms contained in it. At three of the 
last dredging stations (5847-5849) samples were obtained by the use 
of the ‘‘Albatross’’ bottom-sampler and these were treated after 
the manner of those taken at the hydrographic stations. 
At the hydrographic stations of the regular series (see footnote 
below) samples were taken on two of the bimonthly eruises, excep- 
tion being made of a few stations at which the bottom was too hard to 
permit of the penetration of the instrument. A set of samples was 
first taken with the Ekman tubular bottom-sampler. This instrument, 
as already stated, was found to be inadequate for our requirements. 
; 
24 We do not say ‘‘at all of the hydrographic stations,’’ since each of the 
repetitions of the primary stations has been treated in our records as a separate 
station. 
