History
George C. Whipple modified the original all-white Secchi disk to “…a disc about 8 inches in diameter, divided into quadrants painted alternately black and white like the target of a level-rod…” The black and white Secchi disk is the standard disk currently used in limnology investigations and marine water quality studies.
Read more about this topic: Secchi Disk
Famous quotes containing the word history:
“The history of work has been, in part, the history of the worker’s body. Production depended on what the body could accomplish with strength and skill. Techniques that improve output have been driven by a general desire to decrease the pain of labor as well as by employers’ intentions to escape dependency upon that knowledge which only the sentient laboring body could provide.”
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