SECT. 4] 



447 



Work of this type was undertaken at least as early as 1943 by Joseph and 

 Wattenberg (1944) who developed maps showing regional differences in light 

 transmission of the Kattegat and of the area west of Lim Fjord. 



More recently, Joseph (1955) has described specialized instrumentation which 

 he has used to develop detailed cross-sections and maps showing the correlation 

 between important oceanographic features and the transmittance properties 

 of the water. 



Fig. 27. The Coastal Survey meter designed by R. W. Austin measures both a and K. 



Similar work has been done by Jerlov (1953) who has developed particle 

 distribution cross-sections from scattering measurements. 



Russian oceanographers are also using this technique and Kozlyaninov 

 (1958) has described a section through the North Pacific current by trans- 

 mittance measurements. 



Equipment of advanced design is being used in the United States for coastal 

 and harbor surveys. This equipment, called a "Water Clarity Meter", was 

 designed by R. W. Austin (1959) and is shown in Fig. 27. 



