The Long Room, National Gallery of Practical Science, London, c 1840.

Etching by Thomas Kearnan showing apparatus and visitors in the Adelaide Gallery, Adelaide Street, The Strand, London. The gallery claimed to 'Blend Instruction with Amusement' and promoted 'the astonishing powers of electricity with the wonders of optical illustration'. There were promenade concerts and daily scientific lectures. The gallery also housed Antoine Claudet's (1797-1867) photographic studio.