James Watt

Scottish inventor, chemist, and mechanical engineer James Watt was born in Refrewshire, Scotland in 1736. He lived in Glasgow, Scotland and later Handsworth, England where he died in 1819 at the age of 83. He is best known for the Watt steam engine, which improved upon the Newcomen steam engine design. His work encouraged fundamental changes during the Industrial Revolution in Great Britain and around the globe.

James Watt was employed as an instrument maker in Scotland at the University of Glasgow. This is where Watt grew interested in steam engines and the technology behind them. While studying the concept, he realized the contemporary design of the engines wasted a significant amount of energy since it repeatedly cooled and reheated the cylinder. To remedy this, Watt came up with an enhanced design called the “separate condenser” that radically improved efficiency and power while decreasing wasted energy. This design was also more cost effective, and Watt eventually adapted the engine to produce rotary motion, which significantly broadened its application beyond just pumping water.

The engine design was a phenomenal breakthrough, but Watt faced great difficulty financially when he tried to commercialize the invention. In 1775, he partnered with Matthew Boulton, forming the Boulton and Watt partnership that eventually became a huge success making Watt a wealthy man. Even after James Watt retired, he continued to perfect new inventions such as the centrifugal governor and indicator diagram design.

Watt had many inspirations during his time, most notably, Adam Smith, Joseph Black, John Roebuck, and many others. Surprisingly, young James did not attend school on a regular basis. During his childhood, his mother often home schooled him, but Watt later went to Greenock Grammar School where he exhibited great engineering skills, manual dexterity, and mathematical abilities. Despite his great talents and mental capacity, Watt remained uninterested in subjects like Greek and Latin.

At the age of eighteen, Watt’s mother passed away and his father’s health began declining. Around this time, Watt headed to London for a year where he studied instrument making, later returning to Scotland where he settled in the major city of Glasgow. It was here that Watt setup his own business making instruments. He crafted and repaired items like parallel rulers, brass reflecting quadrants, scales, barometers, and telescope parts along with many other things. Soon, though, the Glasgow Guild of Hammermen blocked his business application because he had not served the seven year minimum apprenticeship required, even though he was the only mathmatical instrument make in all of Scotland at the time.

James Watt did not let this phase him, and later worked for the University of Glasgow where he served the astronomical instruments that needed careful attention. Along with his biggest constribution, the Watt steam engine, he also developed essential concepts like horsepower. Later on, the “Watt” (SI unit of power) was named after him. 0

Perhaps Watt would have never grown interested in steam engine design if it wasn’t for his friend, John Robison, who brought his attention to them in 1759. At the time, the Newcomen engine design had been in use for almost fifty years. It was used to pump water out of mines, and had barely been changed since it was first implemented. Despite never having seen a steam engine in operation, Watt began experimenting with the concept. He attempted to make a model, but it didn’t satisfy him. Not discouraged, Watt continued his work and began to study the subject extensively. He soon recognized the importance of the thermal energy absorbed/released during a constant-temperature process (called “latent heat”) and the role it played in the functioning of the engine. Unknown to Watt at that time, this was something his friend and inspiration Joseph Black had already discovered a few years prior. Watt realized that the present steam engine design was very basic, to no fault of its original inventors since the study of thermodynamics would not really begin for about 100 years.

It was in 1763 that Watt requested permission to do a repair on a Newcomen model steam engine that belonged to his university. Even after James repaired the model, it barely functioned. Watt continued his experiments, and demonstrated how wasteful the design was by showing about ¾ of the thermal energy of the steam was consumed by heating the engine cylinder each cycle. Watt realized that this was completely wasted energy, because another step in the cycle injected cold water into the cylinder in order to reduce the pressure of the steam. This led to the cylinder being continuously reheated and recooled, wasting about 75% of the thermal energy being produced that could be more efficiently transformed into mechanical energy.

In May 1765, Watt made this critical adjustment by causing the steam to condense in a separate chamber away from the piston. He also re-designed the engine so the temperature of the cylinder remained at the same temperate as the injected steam by fitting it with a “steam jacket”. This meant very little energy was absorbed, giving it more power to work more efficiently. Later that same year, Watt presented the first working model. Although he had a design that could potentially be implement for more cost effective and efficient production, he faced significant difficulties in creating a full-scale engine. He got some funding from Black, and a great amount from Roebuck.

Working as partners, Boulton and Watt soon had their first commercial engines installed and working in the year 1776. At the time, Boulton and Watt did not manufacture these engines. Instead, Watt provided detailed drawings of them to others. These engines were incredibly large, and required their own dedicated buildings. Boulton and Watt charged a yearly fee for their use, equivalent of 1/3 the coal value saved by the new engine design.

Watt retired wealthy in 1800, the year that his partnership with Boulton expired. Their partnership was transferred to their sons who later added William Murdoch to their firm, leading to even greater prosperity. Watt died on August 25, 1819 in his home. He was 83 years old and was bured in the graveyard of St Mary’s Church in Handsworth. Since, the church has expanded and Watt’s grave is now inside the church walls.