Abstract
In August, 1932, after the kind guidance of Prof. S. Fujiwhara and Prof. R. Sekiguti we made the observations on the damping of the intensity of solar radiation in the water of the Lake Asinoko, which was done by the use of the instrument of our own design and make. The empirical formula determined from our data is as follows; S=1.36e-0.1_??_gr.cal/min._??_ (10th)d: depth in meter.
