Engraving entitled 'View of the Pneumatic Railway in Operation with Trains on a Double Line Pasing a Station'. The idea of pneumatic, or atmospheric propulsion for a railway originated with George Medhurst in around 1810. His system involved air being pumped along a pipe, pushing a piston which would drag a vehicle along rails outside the pipe. It was considered that pneumatic propulsion had potential advantages over steam, in particular the fact that as a pneumatic railway would not need a locomotive to pull it, trains would be lighter and tracks consequently cheaper to build. A number of pneumatic railways were actually built during the 1840s, including Brunel's South Devon Railway, but the technology could not displace steam, which was by then well established.
© Science Museum / Science & Society Picture Library