British physicist (1820–1893) who answered the question, why is the sky blue? (It’s due to the scattering of impinged sunlight by dust and other colloidal particles in the air.) ANS, one page, 6.75 x 2.5, no date. Brief note to a collector. In full: “My hand shakes a little, but you have here the best that I can give you.” A vertical fold to left side, two tack holes to top, some light pencil remnants, and some scattered light soiling, otherwise fine condition. RRAuction COA.
