Coloured exhibition drawing

Coloured exhibition drawing, 29.75" x 27" (vertical), scale 1:48, showing sectional elevation and plan of complete lay-out for Boby vertical water softening plant, 1932, erected for the London, Midland and Scottish Rly. Co. at Preston (Lancs) with description (hand printed) of general lay-out, the softening process employed, and the sludging arrangements, plant capacity 480,000 gallons per hour, completed July 1932