Numerical results of the Mie theory of scattering of light energy by suspended particles have been applied to light extinction measurements obtained from waters of Chesapeake Bay and its major tributaries. A Beckman Model DU Quartz Prism Spectrophotometer with 10 and 50 cm liquid absorption cells was used on raw and filtered samples to determine the extinction as a function of wave length. Extinction in these waters is primarily due to absorption and scattering by suspended materials....