Anthony Mount displayed this unusual historic model locomotive of Salamanca at a Bristol exhibition. It was the world’s first commercially viable steam locomotive.

Matthew Murray (1765 – 1826) was an innovative designer in many fields including steam engines, machine tools and textile machinery. In 1812 his firm supplied John Blenkinsop, manager of Brandling's Middleton Colliery, near Leeds, with the Salamanca, the world’s first commercially successful steam locomotive.

The double cylinder was Murray's invention. He paid Richard Trevithick a royalty for the use of his patented high pressure steam system, but improved it by using two cylinders rather than one to give a smoother drive.

Because only a lightweight locomotive could work on the cast iron rails of the day without breaking them, the total load they could haul was severely limited. Then, in 1811, Blenkinsop patented a toothed wheel and rack rail system. The toothed wheel was driven by connecting rods, and meshed with a toothed rail at one side of the track. This was the first rack railway, and had a gauge of 4 ft 1½ ins.

Once a system had been devised for making malleable iron rails, around 1819, the rack and pinion motion became unnecessary, apart from later use on mountain railways. However, up to then it had enabled a small lightweight locomotive to haul loads totaling at least 20 times its own weight.

Salamanca was so successful that Murray made three more: probably called Lord Wellington, Prince Regent and Marquis Wellington. The third locomotive  was sent to the Kenton and Coxlodge Colliery Waggonway near Newcastle upon Tyne, where it appears to have been known as Willington. There it was seen by George Stephenson, who modelled his own locomotive Blücher on it, minus the rack drive, and so less effective.

After two of the locomotives exploded, killing their drivers, and the remaining two were increasingly unreliable after at least 20 years hard work, the Middleton colliery reverted to horse haulage in 1835.