The Science Museum

A quick visit to the main floor of the Science Museum, next to the Natural History Museum, just to see the steam engines. This one was built by Boulton and Watt and is

..the oldest, mainly unaltered rotative engine in the world. Built by James Watt in 1788, it incorporates all his most important steam engine improvements. This engine operated at Boulton's Soho manufactory in Birmingham where button, snuffboxes, and other small decorated metal items were made. This engine drove 73 metal polishing - 'lapping' - machines for 70 years. 

This is one of the machines that changed the world. It is amazing that it still exists.

The engine below was

...constructed in 1903 by the Burnley Ironworks Company for the Harle Syke Mill, Burnley. It is an example of a 'horizontal' engine, a type that was widely used after 1850, and was direct acting, doing away with the giant rocker beams of earlier engines. This one is typical of many built during the period and it worked right up to 1970.

Here is a closer view of the engine and the periodic expulsion of steam as part of the engine cycle.

I find it amazing that such complicated pieces of exactly machined pieces of equipment are still in working order after more than a century.