page_title: Old Bess (beam engine)
hierarchical_section_title: Old Bess (beam engine)
caption_attribution_description: English: Watt's beam engine Old Bess, dating from 1777 and built by Boulton and Watt
context_page_description: Old Bess is an early beam engine built by the partnership of Boulton and Watt. The engine was constructed in 1777 and worked until 1848.
  The engine is most obviously known simply for being an early example of an engine built by Boulton and Watt. However it also played a far more important role in the development of steam engines for being the first engine designed to work with an early cutoff, and so to use the expansion of the steam for greater efficiency.
  It is now preserved in the Power Gallery of the Science Museum, London. It is the oldest surviving Watt engine, and the third-oldest surviving beam engine.
context_section_description: Old Bess is an early beam engine built by the partnership of Boulton and Watt. The engine was constructed in 1777 and worked until 1848.
  The engine is most obviously known simply for being an early example of an engine built by Boulton and Watt. However it also played a far more important role in the development of steam engines for being the first engine designed to work with an early cutoff, and so to use the expansion of the steam for greater efficiency.
  It is now preserved in the Power Gallery of the Science Museum, London. It is the oldest surviving Watt engine, and the third-oldest surviving beam engine.
caption: Old Bess, as now preserved in the Science Museum, London
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