Which Scottish engineer gave his name to the SI unit of power?

The Scottish engineer who gave his name to the SI unit of power was James Watt.

Watt was born in Greenock, Scotland, in 1736 and worked as a mathematical-instrument maker before becoming deeply involved with steam technology at the University of Glasgow. His most important improvement was the separate condenser, which prevented steam engines from wasting energy by repeatedly cooling and reheating the main cylinder.

Watt did not invent the first practical steam engine; Thomas Newcomen’s earlier engine was already used for pumping water. Watt’s improvements made steam power substantially more efficient and economical, and his partnership with businessman Matthew Boulton helped bring the technology into widespread industrial use. That is why Boulton, although closely associated with Watt, is not the answer.

The watt measures the rate of energy transfer: one watt equals one joule per second. The unit was named for Watt in the nineteenth century and was adopted into the International System of Units in 1960. The symbol is an uppercase W.