William Donaldson Clark was a wealthy cotton cloth printer who used his knowledge of chemistry in his practice as an amateur photographer. He employed the dry collodion process which made outdoor work more practical. Although it required exposure times of up to a quarter of an hour, the technique resulted in subtle effects of light and dark. Clark worked with the landscape painter, Horatio McCulloch, and his own landscape photographs have a similar sophistication. They include some remarkable views of Edinburgh. He died in 1873 when he fell from the top of a tram car travelling from Newington into the city.