Page:Philosophical Transactions of the Royal Society A - Volume 184.djvu/11

Rh action through clear water 1st Exposure action through turbid water 147 1 = 152 1.037 172 1 181 1.052 2nd 9) 3rd 204 212 1 1.055 1 39 1 Mean = 1.05 4.982

The photographic light passing through the clear water = = 4.70 times that 1.05

passing through the turbid water.

Using the formula I' = Ie - MY log 4:7 = 1.54756 = 17p1 Hi= .910 for each inch of turbid water.

The optical measures of the light passing through the clear and turbid cells in the w o directions were 3.15 inches clear water, 48.5; turbid water, 18.2. 1.7 485; 28.5.

Taking the measurement of the light passing through the 3:15-inch cell as lying on the curve in the formula I' = Icy, log 48.5 - log 18.2 = u X 3.15, Mi 311.

If we take the measure of the 1.7-inch water, we have

log 48.5 - log 28.5 = M X 17, M = 313. Mean value = 312.

Now mean value of x = .9105. Now A- 105 My u 14 therefore A-+ -9015 312 x 105 = 306.6.