^ Lira, Carl. Biography of James Watt. egr.msu.edu. 2001 [5 July 2010].
^ Thurston, Robert Henry. A history of the growth of the steam-engine. The International Scientific Series. New York: D. Appleton and Company. 1878: 80.
^ Muirhead, James Patrick. The life of James Watt: with selections from his correspondence 2. John Murray. 1859: 10.
^ Klooster, John W. Icons of invention: the makers of the modern world from Gutenberg to Gates. Icons of invention 1. ABC-CLIO. 2009: 30. ISBN 978-0-313-34743-6.
^ Joseph McCabe. A Biographical Dictionary of Ancient, Medieval, and Modern Freethinkers. Haldeman-Julius Publications. 1945 [17 August 2012]. He made such improvement in the crude steam-engine that had been invented before his time that he is usually described as the inventor. "His many and most valuable inventions must always place him among the leading benefactors of mankind," says the account of him in the Dictionary of National Biography. He was an accomplished man. He knew Greek, Latin, French, German and Italian and was very friendly with the great freethinking French scientists. Andrew Carnegie has written a life of him and describes him as a deist who never went to church.
^ Tann, Jennifer. James Watt (1736–1819). Oxford Dictionary of National Biography. Oxford, England: Oxford University Press. 2004.
^ Thomas, Henry; Thomas, Dana Lee. Living adventures in science. Ayer Publishing. 1954: 25.
^ 12.0 12.1 Muirhead, James Patrick. The life of James Watt: with selections from his correspondence. J. Murray. 1858: 74–83 [17 August 2011].
^ 13.0 13.1 Frazer, Persifor. Journal of the Franklin Institute. 1859: 296–297 [17 August 2011].
^ Kelly, E.R. The Post Office Directory of Birmingham. London: Kelly and co. 1878: 176.
Dickinson, H. W. James Watt: Craftsman and Engineer. Cambridge University Press. 1935.