In a previous post (31st August 2015)) I wrote briefly about Stieglitz’s ‘Equivalents’. In her book Weatherland Alexandra Harris discusses the work of Alexander Cozens, who defined a series of ‘Sky-types’ for artists is 1785, and John Constable, who in 1821-22 made cloud studies, see opposite. Both can be seen as non-photographic precedents for the ‘Equivalents’.