Compound lever Compound lever The compound lever is a simple machine operating on the premise that the resistance from one lever in a system of levers will act as power for the next, and thus the applied force will be amplified from one lever to the next (as long as the mechanical advantage for each lever is greater than one). Almost all scales use some sort of compound lever to work. Other examples include nail clippers and piano keys. A lever arm uses the fulcrum to lift the load using and intensifying an applied force. In practice, conditions may prevent the use
Barker lever "contrivance" was named after Charles Spackman Barker (1804-79), engineer and organ-builder. A similar lever was developed by David Hamilton in 1835, and there has been debate whether Barker stole the design. Barker lever The Barker lever is a pneumatic system which multiplies the force of a finger on the key of a tracker pipe organ. It employs the wind pressure of the organ to inflate small bellows called "pneumatics" to overcome the resistance of the pallets (valves) in the organ's wind-chest . This lever allowed for the development of larger, more powerful organs still responsive to the human hand. These