The following conclusions may be drawn from this investigation: (1) The photometer is an accurate and dependable device for measuring light absorption by turbid soil and water solutions when the soil particles are of nearly constant size. The tests made with the soil that had passed through a 100-mess sieve proved this fact, also, the tests made with the composite soil gave vary accurate results. (2) the composite runoff soil samples from the three slopes must have contained particles of approximately the same size. This is shown by the accuracy of the results obtained with this soil. / Master of Science