Old English steam "vapor, fume, water in a gaseous state," from Proto-Germanic *staumaz (source also of Dutch stoom "steam"), of unknown origin. Meaning "vapor of boiling water used to drive an engine" is from 1690s, hence steam age (1828) and many figurative uses, such as let off steam (1831, literal), blow off steam (1857, figurative), full-steam (1878), get up steam (1887, figurative). Steam heat is from 1820s in thermodynamics; as a method of temperature control from 1904.
We have given her six months to consider the matter, and in this steam age of the world, no woman ought to require a longer time to make up her mind. [Sarah Josepha Hale, "Sketches of American Character," 1828]
whistle n.
"tubular musical instrument sounded by blowing," Old English hwistle (see whistle (v.)). Meaning "sound formed by pursing the lips and blowing" is from mid-15c. To wet one's whistle "take a drink" (late 14c.) originally may have referred to pipes, or be an allusion to the throat as a sort of pipe. Phrase clean as a whistle is recorded from 1878. Railroad whistle-stop (at which trains stop only if the engineer hears a signal from the station) is recorded from 1934.