3 
made with the vertical at the time the messenger was released. 
“Soundings” and “‘depths of observation”’ are given in meters. The 
sounding recorded is usually that obtained by the hydrographic cable. 
The direction from which the wind blew is given in degrees and the 
force of the wind is noted by values according to the Beaufort scale. 
A number following ‘‘bottom sample” indicates that the sample 
was retained and is now stored at the Scripps Institution of Oceanog- 
raphy. The ‘‘type” of the bottom sediment is that which was 
recorded at the time of collection. Under ‘‘additional observations” 
are recorded collections and analyses other than those for tempera- 
ture, salinity, and bottom samples. The following symbols have been 
used: 
O = Analyses for the dissolved oxygen content of samples. 
Pl = Quantitative surface plankton collection. 
PO, =Analyses of water samples for phosphate content. 
SiO, =Analyses of water samples for silica content. 
NO, =Analyses of water samples for nitrite content. 
Boron= Analyses of water samples for boron content. 
The columns contain the following data: 
Estimated depth.—This is the depth to which the closing bottles 
were lowered. This column has only been filled in when the cable 
was vertical. Depths are in meters below the surface. 
Depth by pressure.—This column contains the depths as computed 
from the values obtained by using an unprotected reversing thermom- 
eter in conjunction with a protected thermometer. Where the 
wire angle is zero the comparison of the estimated depth with the 
thermometric depth gives a measure of their accuracy. In those 
cases where the cable was not vertical the depths of sampling are 
based entirely upon the thermometric depths. As unprotected 
thermometers were not attached to all the sampling bottles, depths 
at which certain of the bottles closed had to be obtained by inter- 
polating upon a graph constructed from the available observations of 
thermometric depths for that cast. 
Temperature.—This column contains the corrected temperature in 
°C. If duplicate thermometers were used the value recorded is the 
average of the two corrected readings. 
Chlorinity— Determined by titration with silver nitrate solution 
standardized against ‘‘standard sea water.”’ Reported as grams per 
kilogram of sea water. 
Salinity Obtained from the chlorinity by reference to Knudsen’s 
Hydrographical Tables. Reported as grams per kilogram of sea 
water. 
o;—This is defined as o;,=(ps,1,.—1)X10°, where p;,;,. is the 
specific gravity of the water in situ not corrected for pressure. o; 
should not be confused with o,, as o,=(s,—1)X10°, where s, is the 
76260—34——2 
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