Bidder, (1806-1878), portrayed here as a child prodigy aged thirteen, was known as the 'Calculating Boy'. He performed public demonstrations of his arithmetical skills throughout Britain as a child and became a civil engineer, inventing the railway swing bridge. In 1846 he worked on the development of transatlantic cables with the Electric Telegraph Company and later designed the Royal Victoria Docks which opened in 1856. He was also a parliamentary advisor.
© Science Museum / Science & Society Picture Library