Compound lever could be measured. 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
Lever frame of them have been taken out of use. The lever frame is located in the signal box, which can be a building at ground level or a tower, separated from or connected to an existing station building. Early lever frames were also built as "ground frames" next to the track, without any form of shelter and were usually operated by traincrew and not permanently staffed. Especially in England, lever frames with the pivot underneath the floor of the signal box were common (as seen on the photo on the left). This design's relatively short lever angle is a major disadvantage,