Greenock-born Watt added a separate condenser to the engine ... he made to the Newcomen steam engine," said the head of the James Watt School of Engineering, Professor David Cumming.

PUMPING STATION WORKER:What we're looking at here, is James Watt's separate condenser - his most important invention. PUMPING STATION WORKER:The original engine by Thomas Newcomen you had to heat ...

The plaque reads 'In 1765, James Watt, in working to repair this model, belonging to the Natural Philosophy Class in the University of Glasgow, made the discovery of a separate Condenser ...