The block and pulley was a system of two or more wheels on an axle - the pulley - with cable threaded between them. The pulleys were then assembled in pairs or blocks; one then moves with the load, whilst the other stays still. In this way the mechanism did most of the work, using leverage to relieve the stress on its users. This allowed sailors to lift objects far too heavy for them, improving the cargo capacity and therefore efficiency of shipping. The variation on the block and pulley - or tackle - system used at Syracuse was designed by the well-known Greek inventor Archimedes (287-212BC), credited with many useful inventions during his lifetime and now considered to be the most important mathematician of the ancient world.
