Engraving showing a stone block being landed on the rock from one of the praams, or stone lighters, using the sheer crane (top and centre left). The lower image shows a cross-section of a praam carrying a load of blocks. Upper right shows stone blocks from the Smeaton being transferred to a praam. The centre image shows the foundation pit being drained of water to the right with the forge in operation to the left, with the section of another of the boats (below). Illustration from 'An account of the Bell Rock Light-house: including the details of the erection and peculiar structure of that edifice' by Robert Stevenson (1772-1850), designer of the Bell Rock Lighthouse, published in Edinburgh in 1824.
© Science Museum / Science & Society Picture Library