Boring machine, yard No 642, early 19th century.
© Science Museum / Science & Society Picture Library
Boring machine made by Henry Maudslay (1771-1831). This machine carries out the boring of shells in two areas. One drill bores the hole for the pivot pin that passes through the shell on which the sheave runs. The other bores a larger, initial hole at right angles that will be elongated by the mortising machine chisel to form the slot for the sheave. A shell and sheave are integral parts of a pulley block used in the management of the sails of ships. The development of the pulley block was fundamental to the workings of a ship as it meant heavier loads could be carried with less power. Increasing the number of pulleys increased the weight that could be moved.