Mechanics · Vol. I|Lever, pulley, and screw|c. 260 BCE (described)

Lever, pulley, and screw

c. 260 BCE (described)

A lever trades distance for force. A pulley redirects it. A screw turns rotation into a slow, huge push. These ideas are older than any one name, but Archimedes stated the law of the lever with a clarity that later engineers could reuse. Simple machines are not gadgets. They are the grammar of mechanics.

Archimedes of Syracuse (description) · Mediterranean

Lever, pulley, and screw — Original plate drawn for this atlas. Not a photograph of a museum object or a copyrighted portrait.

How the mechanism is arranged

A lever trades distance for force around a fulcrum. Load × load-arm = effort × effort-arm.

How it works

Place a rigid bar on a fulcrum; a small force far from the fulcrum balances a large force near it.
Run a rope over a wheel (pulley) to change direction, or combine wheels to multiply force.
Wrap an inclined plane around a cylinder (screw) to convert turning into linear motion.

Why it mattered

Let people lift loads heavier than themselves.
Made cranes, presses, and pumps possible.
Gave later physics a set of worked examples.

Who turned the wheel

c. 287–212 BCEArchimedes

What it unlocked

For further study

Archimedes, On the Equilibrium of Planes. Law of the lever.
Smithsonian. Simple machines in teaching collections.

Check

If you want more force from a lever, what must you give up?