345 



APPENDIX B 



ixstkictions i"ok cooperators in thk marine borer survev of 

 San Francisco Bay 



1. DETERMINIXC, THE SALINITY OF WATER 



Oi!TAiNiN(; Water Samples 



Sampling. — Samples of water should be taken always at the same determined 

 stations. It is suggested that stations not already established at the date of receipt 

 of these instructions be selected in consultation with the Forest Service engineers.* 

 Samples should be taken at least once each week, from both the surface and near the 

 bottom, and at both high and low tide. This will make not less than four samples 

 for each station, at each weekly (or more frequent) period. Care should be taken to 

 take the bottom samples each time at the same distance from the bottom (sa>' 1 foot). 

 This can best be accomplished In- driving a nail in the structure from which the sampling 

 is done, at a convenient point to the operator, and after determining the proper dejith 

 at the first sampling, to record the length of line used and indicate it b\- a knot in 

 the line; then drop the sampling bottle always to the same depth from the nail lor 

 the bottom sample. 



Apparatus. — Salinity samples may be taken either with a special lead-weighted 

 copper salinity bottle such as that used by the S. P. Co., or with any suitable stout 

 glass bottle ot 12-oimce to 1-pint capacity", weighted so as to permit its sinking when 

 empty. The common 12-ounce citrate of magnesia bottle is excellent. If a glass bottle 

 is used it must be supplied with a solid stopper, through which a stout wire is driven 

 and clinched on the under side, while the protruding end on the upper side is formed 

 into a small ring. The lowering cord is then tied secureh', say a foot from its end, to 

 the ring in the stopper wire, and the end of the cord fastened tightly around the neck 

 of the bottle so as to allow a few inches oi slack between neck fastening and stopper 

 ring. The friction of the stopper will permit the lowering of the closed bottle to the 

 desired depth in the water, where it can be unstoppered by a quick jerk of the line. 

 Should premature pulling of the stopper occur, it can be detected by the too earh' 

 appearance of bubbles due to filling. If the citrate of magnesia pattern is not used, the 

 bottle should in any case be as small-necked as will permit the proper wiring of the 

 stopper, in order to a\oid contamination of the sample by inwash of shallow water 

 while raising the bottle. 



Storaiie. — Each sample of water should be transferred from the samjiling bottle to a 

 tlioroughly cleaned and drained storage bottle of approximately the same size, prefer- 

 ably glass stopperetl, which should be tag-labeled with the number or name of station, 

 date and hour of sampling, state of tide, whether sample is from top or bottom, and, 

 for the latter, the height bom bottom and approximate depth below surface at wliich 

 taken. Analysis of the samples can then be made at con\enieiice, except that anahsis 

 results shf)uld lie sent in currently, without too great dela\'. 



Sliipphii;,. — If the water samples must be transported by common carrier, to 

 the laboratory or otherwise, a case constructed in accordance with the accompanxing 

 diagram will be found to comliine a high degree of safety and convenience. 



*Address by letter, C. L. Hill, Ferry Building, San Francisco, California; telephone Kearny 5869. 



