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MISCELLANEOUS 



9613 



the other is for the range of temperatures from 15° to 30° C. Both diagrams are used 

 in the same way. Enter the diagram with the temperature at depth on the scale at 

 the top of the diagram and drop vertically to the diagonal line representing the salinity, 

 then follow horizontally to the diagonal line representing the depth of the observation, 

 and from here drop vertically to the abscissa scale at the bottom of the diagram and 

 read the velocity of sound. If the upper series of depth curves is used the upper of the 

 two velocity scales should be used, but if the lower series of depth curves is used the 

 v^elocity should be read from the lower of the two velocity scales. 



9673. Velocity Correction Factors 



For deriving the factors used in computing velocity corrections to be applied to 

 echo soundings, to account for the deviation of the actual velocity from the calibration 

 velocity of the echo-sounding instrument, table 35 is given. The use of the factors is 

 explained in 5613 and they are used in the example of velocity correction computations 

 in table 20. 



Table 35. — Velocity correction factors 



