Page:Proceedings of the Royal Society of London Vol 69.djvu/332

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Dr. W. E. Wilson.

The percentage transmitted is p, therefore the radiation before reflection from the heliostat is -!--- TT sin 2 p.

At reflection q per cent, is transmitted, therefore the radiation re- ceived by the radio-micrometer is

- (I)-

Also the radiation received from the hot tube is

(2)