Watt, James (1736-1819), was a Scottish engineer whose improved engine design first made steam power practicable. Crude steam engines were used before Watt's time, but they burned large amounts of coal and produced little power. Their reciprocating (back-and-forth) motion restricted their use to operating pumps. Watt made steam engines more efficient by inventing the separate condenser. This device changed steam back into water by cooling. Watt's later improvements made possible the wide application of steam engines, contributing much to the growth of modern industry.