1) Report on temperatures of water in Derwent Lake, 1830; 2) 28 November 1832, describes some recent phenomena on Derwent Water, a day of heavy fog, being followed by a day of cold frost, it was then noted that the surface of the lake presented "an extraordinary exhibition of prismatic colour", with the water appearing illuminated like a rainbow; 3) 11 January 1838, comments on Rive's paper on optical phenomena at Mont Blanc, which describes an apparent double illumination of the peak after sunset. He feels this might be caused by distant cloud temporarily occluding the sun, rather than the enhancement of reflected rays on the peak by local humidity.
Otley (1766-1856) was an amateur scientist and the author of the first tourist guide to the Lake District and Dalton’s companion on many of his visits there.
Dated at: Keswick (Cumberland).