Wheel and Axle - Simple Machines - Who invented the wheel?
Quatr.us answers questions
Upgrade /Log in
Options /Log out
Print
About
Africa
Egypt
Mesopotamia
Early Europe
Greece
Rome
China
India
Central Asia
Medieval
Islamic Empire
Native Americans
S./Central America
American History
Biology
Chemistry
Geology
Math
Physics
Weather
Food
Judaism
Christianity
Home

Wheel and Axle

Standard of Ur wheel
A cart on the Standard of Ur (Iraq, 2600 BC)

May 2016 - Wheels do not exist in nature, and no animals use them except people. Even people didn't use wheels until the early Bronze Age, around 3500 BC, much later than the other simple machines (the lever and the inclined plane).

The earliest evidence for people using wheels comes from Sumeria (modern Iraq), about 4000 BC, just about the time when people first began to live in cities. The earliest wheels were probably not wagon wheels, but pottery wheels. Soon after that, though, maybe around 3700 BC, people in Central Asia were making wagon wheels. You can see from the pictures that spokes developed later than solid wheels.

Nineveh Wheel
Wheeled wagon carrying prisoners of war
(Nineveh, Iraq, 700 BC)

Wheels help people do work in two ways. First, like levers or inclined planes, wheels allow you to do something easy for a longer time, instead of doing something hard for a shorter time. If you turn a large wheel fixed to an axle, the axle will also turn. You can turn the large wheel easily (but it takes a lot of turning to go all the way around). The axle will go around a much shorter distance, but with more force. So you can use a wheel to create a mechanical advantage - you can turn something heavy, by spinning a large wheel attached to an axle that is attached to the heavy thing. That's how a pencil sharpener works. Or, you can do it the other way around - use a lot of force to turn the axle, and that will spin the wheels really fast. That's what cars do. You get more mechanical advantage with bigger wheels and thinner axles - the mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle - but bigger wheels and thinner axles are also more likely to break, so you have to find the best proportion for your specific use.

Pencil Sharpener
How is this a wheel?

Also, wheels on a wagon only touch the ground at one spot at a time, keeping the rest of the wagon off the ground. This makes less friction, so that the wagon is easier to move than if you were pulling it along like a sled.

Wheels are the most important part of pottery wheels, wagons and cars, but also of wheelbarrows, spinning wheels, water wheels, windmills, and pulleys.

Learn by doing - build a windmill to generate electricity

Bibliography and further reading about simple machines:

Levers
Inclined Plane
Machines
Physics
Quatr.us home


Professor Carr

Karen Eva Carr, PhD.
Assoc. Professor Emerita, History
Portland State University

Professor Carr holds a B.A. with high honors from Cornell University in classics and archaeology, and her M.A. and PhD. from the University of Michigan in Classical Art and Archaeology. She has excavated in Scotland, Cyprus, Greece, Israel, and Tunisia, and she has been teaching history to university students for a very long time.

Professor Carr's PSU page

Help support Quatr.us!

Quatr.us (formerly "History for Kids") is entirely supported by your generous donations and by our sponsors. Most donors give about $10. Can you give $10 today to keep this site running? Or give $50 to sponsor a page?

Now that the weather's nice, try some of these outdoor activities! How about bicycle polo, or archery for a Medieval Islam day? Or kite flying or making a compass for a day in Medieval China? How about making a shaduf for a day in Ancient Egypt? Holding an Ancient Greek Olympic Games or a medieval European tournament? Building a Native American wickiup?