Cloud horizon

Night view of the rolling clouds below Mount Guajara, Tenerife, Canary Islands.
Inscribed in ink: 'The cloud horizon at Guajara as seen by moonlight: showing the summit of Grand Canary above the clouds in the distance.' This particular watercolour features as the bottom half of plate XXXII in Smyth's paper 'Astronomical experiment on the peak of teneriffe, carried out under the sanction of the lords commissioners of the admiralty', published in the Philosophical Transactions of the Royal Society, vol. 148, 1858.
From the 'Tenerife Papers of Charles Piazzi Smyth', a scrapbook of watercolours and stereo plates from Smyth's 1856 astronomical expedition to a volcanic mountain range in Tenerife.