Ivan Ivanovich Polzunov (Russian: Иван Иванович Ползунов (1728 – 1766) was a Russian inventor. He is said to have constructed the first two-cylinder steam engine in the world (in 1763).
Illustrations of his two-cylinder engines here and here. The machine comprised a pair of Newcomen atmospheric engines served by one boiler. Photograph here shows the arrangement used to direct steam and water injection to one cylinder or the other.
The engine is shown working two large bellows for furnace-blowing. The two pistons worked alternately, providing more regular output from the bellows than would have been the case with a single-cylinder engine of equivalent power, although the fuel efficiency would probably have been lower.
Polzunov's boilers incorporated a float valve which he invented to maintain the boiler water level
Sources of Information
-  'Engines of our Ingenuity' No. 1616: IVAN POLZUNOV by John H. Lienhard