Adam Hart-Davis takes a ferry across the Mersey to celebrate the work of the North West's unsung heroes of science in the last of the current series.

He relives his childhood love of Meccano, invented by Frank Hornby, before moving on to celebrate the work of other scientists and innovators, including Arthur Doodson, who perfected a way to predict the tides; Alastair Pilkington, who invented a way of producing flawless glass; and Jeremiah Horrocks, the founder of English astronomy, who was the first to track the orbit of Venus and revolutionised how astronomers consider the universe.