The portable developing tent was patented by W. R. Baker of 9 Belmont Road, Wallington, on 22 December 1890 number 20864. It was designed for processing but the tent could also be used as a changing bag and focusing cloth.A similar example was sold in The Cyril Permutt Collection of Cameras, Optical Toys and Related Material, 10 November 1988, lot 104.