Compound lever the force of pushing back the stick to the levers and they rub against the wheels, using friction to slow and eventually stop the train. These are everyday applications of this mechanism. A piano key is a compound lever of the first-class, since the fulcrum is between the weight to be moved and the power. The purpose of this lever is to translate a small movement (depression of the key) into a larger and fast movement of the hammer on the strings. The quality of the resulting tone depends on whether the final speed is brought about by gradual or
Darcy Lever constructed with a timber frame with plaster fill and a grey slate roof in the Tudor style. It was located on the high ground that slopes down to Blackshaw Brook, which flowed past the south side of the house near the junction with the River Croal. The hall was demolished in 1951. The growth of the textile industry around Darcy Lever was assisted by the availability of coal. By 1896 John Fletcher owned coal mines at Ladyshore, Little Lever; The Earl of Bradford had a coal mine at Great Lever and the Darcy Lever Coal Company and others had mines