Wheel and Axle - Simple Machines - Who invented the wheel?
Welcome to Quatr.us Study Guides!

Wheel and Axle

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.

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.

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.

replica of Indian churka (500s BC)

A gear is a special kind of wheel with teeth that fit into the teeth of another wheel (so a gear is also a kind of lever, because wheels are a kind of lever). Some kinds of grasshoppers have evolved to have legs with gears in the joints to jump with. Whoever invented gears, the idea spread quickly: Indians were using gears for waterwheels by the 300s BC, Greeks knew about gears by the time of Aristotle, about the same time, and people were also using gears in China. By the early Middle Ages, people all across Afro-Eurasia were using gears to run watermills and windmills.

LeversInclined PlaneMachinesPhysicsQuatr.us home

Please help other teachers and students find us: link to this page from your class page.
Karen Carr is Associate Professor Emerita, Department of History, Portland State University. She holds a doctorate in Classical Art and Archaeology from the University of Michigan. Follow her on Instagram, Pinterest, or Twitter, or buy her book, Vandals to Visigoths.
Karen Carr is Associate Professor Emerita, Department of History, Portland State University. She holds a doctorate in Classical Art and Archaeology from the University of Michigan. Follow her on Instagram or Twitter, or buy her book, Vandals to Visigoths.
Sign up for more free articles and special offers in Quatr.us' weekly newsletter:
We will never share your e-mail address unless you allow us to do so. View our privacy policy. Easy unsubscribe links are provided in every email.
Check out our new ebook: Short and Simple: Ancient Greek Myths! - just out! Twenty-five easy to read, illustrated stories, from Pandora to Medea, Icarus, and the Trojan Horse (you can read these online as samples). Get it this week for just \$14.99, five dollars off the regular price of \$19.99.
Cite this page
• Author: K.E. Carr
• Title:
• Site Name: Quatr.us Study Guides
• Publisher: Quatr.us
• Date Published:
Did you find what you needed? Ask your teacher to link to this page so other people can use it too! Send it in and win a Quatr.us "Great Page!" award!
Sign up for more free articles and special offers in Quatr.us' weekly newsletter:
We will never share your e-mail address unless you allow us to do so. View our privacy policy. Easy unsubscribe links are provided in every email.
Comment on This Article
Quatr.us is loading comments...
(Comments will appear after moderation, if they are kind and helpful. Feel free to ask questions, and we'll try to answer them.)
Cite this page
• Carr, K.E. . Quatr.us Study Guides, . Web. 20 October, 2017
ADVERTISEMENT