The business of brickmaking is very much taken for granted, and the vital role of brick production in the Industrial Revolution has received little attention. Its importance can perhaps be appreciated when we consider the rate of consumption of bricks, in projects which could have hardly been imagined at the beginning of the 19th century – railway viaducts and tunnels, docks, mass housing, factories sewers, etc. A single factory chimney could easily require half a million bricks, many docks and railway viaducts needed tens of millions. The Summit Tunnel through the Pennines, completed in 1841, needed 23 million. In 1849 the first of the Castlefield Viaducts (Manchester) used 50 million. 77 million bricks lined the Severn Tunnel (needing 37,000 tons of Portland cement).