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:
“It’s nice to be a part of history but people should get it right. I may not be perfect, but I’m bloody close.”
—John Lydon (formerly Johnny Rotten)
“If you look at the 150 years of modern China’s history since the Opium Wars, then you can’t avoid the conclusion that the last 15 years are the best 15 years in China’s modern history.”
—J. Stapleton Roy (b. 1935)
“I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young.”
—Thomas Henry Huxley (1825–95)