We went to the exhibition Inventing Impressionism at the National Gallery last night.   I hadn’t realised how key to a knowledge of Impressionism in London was the comprehensive exhibition held by Paul Durand-Ruel and Sons in the Grafton Galleries in 1905, when Roger Fry became an advisor;  nor how large and spacious the Grafton Galleries were, with top-lit exhibition galleries as grand as the galleries at the Royal Academy.   Originally in Grafton Street, it is said to have moved to Bond Street, although there is a picture of its grand premises, described as being in Bond Street, in Building News on 6 May 1892 and it is still listed as being in Grafton Street in 1899.   It held miscellaneous exhibitions, including Manet and the Post-Impressionists in 1910.