History of the Watt Steam Engine

By: Yara Simón  | 
This wood carving depicts James Watts' double-acting steam engine.
This wood carving depicts James Watts' double-acting steam engine. Uwe Zänker / Getty Images

The Watt steam engine, invented by James Watt during the Industrial Revolution, stands as a groundbreaking tehcnological advancement that propelled the world forward through improved forms of transportation. And while Watt did something truly innovative, he also built on the work of previous inventors, including Thomas Savery and Thomas Newcomen.

Learn more about the history of steam power, as well as the Watt steam engine’s impact.


Early Steam History

These early experiments and innovations marked significant miles in the journey toward harnessing the power of steam. They provided the groundwork for future inventors and engineers to build upon, refine and expand upon these concepts.


The origins of steam technology date back to around A.D. 75 when mathematician Hero wrote extensively about air mechanics and properties and presented plans for a basic steam engine.


His design consisted of a hollow sphere with bent tubes protruding from the sides. By filling the sphere with water and placing it over a fire, the heat would vaporize the water, and the resulting steam would escape through the tubes, causing the sphere to rotate. This invention laid the foundation for further advancements in steam technology.

Giovanni Battista della Porta

In the 17th century, Italian scholar Giovanni Battista della Porta realized that steam played a role in creating a vacuum. He theorized that when water converted into steam inside a closed container, it would result in increased pressure, while the condensation of steam back into wter would yield decreased pressure.

Denis Papin

In 1679, French scientist Denis Papin turned della Porta’s theory into reality with a project he called the “Digester or Engine for Softening Bones.” He used a device that resembled a pressure cooker; it became the first practical application of steam pressure.

Papin further refined the concept by incorporating a sliding piston on top of a closed cylinder filled with water. As the water heated up, the steam expanded and pushed the piston upward. When the steam cooled and condensed, a vacuum was created, drawing the piston back down.


The Birth of Steam Engines

In 1698, military engineer Thomas Savery obtained a patent for his innovative steam pump, the “Miner’s Friend.” Savery’s steam pump consisted of a boiling chamber that directed steam into a separate container. Inside the container, there was a pipe with a non-return valve that extended into the water that needed extracting. By pouring cold water onto the steam-filled container, the steam would condense back into a liquid, creating a vacuum that drew water from below through the pipe.

For the Newcomen engine, Thomas Newcomen, an English inventor, took inspiration from Savery’s separation of the boiler and steam cylinder, as well as Denis Papin’s steam-drivem piston. In doing so, he played a crucial role in advancing steam power. In the early 18th century, he introduced the atmospheric engine. The Newcomen steam engine could pump water out of mines. It operated by using steam to create a partial vacuum in a cylinder. The atmospheric pressure would then push a piston downward, enabling the engine to function.


Watt’s Steam Engine

James Watt, an instrument maker who worked at Glasgow University, further improved the design and efficiency of steam engines. In the late 18th century, Watt experimented and developed the Watt atmospheric engine, which incorporated a separate condenser and the ability to harness the expansive force of steam. By isolating the condensation process from the cylinder, he minimized heat loss and maximized power output.

He also introduced the double-acting engine, which allowed for power to be generated in both the upward and downward strokes of the piston. Watt patented his steam engine in 1769. The engine’s efficiency made it suitable for transportation, which helped connect distant region and facilitate the movement of goods.


In 1774, Watt entered into a partnership with Matthew Boulton, an entrepreneur and manufacturer who proved instrumental in the commercial success of the steam engine. Boulton recognized the potential of Watt’s invention and saw an opportunity to mass-produce and market it.

The Impact of the Watt Steam Engine

James Watt’s steam engine played a pivotal role in transforming industries, transportation and society during the Industrial Revolution. The Watt engine powered factories and mills, providing a reliable and efficient source of power.

His invention also led to the early steam locomotive and steam ships to replace animal-drawn vehicles and sail-powered vessels. This, in turn, facilitated the growth of railways and steamships. And this more efficient steam engine revolutionized mining operations by powering pumps that could remove water from mines.


The Watt steam engine also fueled advancements in science, engineering and technological innovation, laying the foundation for further progress.

This article was created in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.