Lever a place to stand, and I shall move the Earth with it' is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria). It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons. A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. In this case, the power into the lever equals
Lever tumbler lock locks were invented in 1778 by Robert Barron of England. These required the lever to be lifted to a certain height by having a slot cut in the lever, so lifting the lever too far was as bad as not lifting the lever far enough. This type of lock is still used today, on doors in Europe, Africa, South America and some other parts of the world. The lock is made up of levers (usually made out of non-ferrous metals). Each lever needs to be lifted to a specific height by the key in order for the locking bolt to