
Left: the Papin engine (1690), the prototype of all steam engines. Right: a Corliss steam engine at the 1876 Philadelphia Centennial Exposition. [2]

In science, engine, etymologically, a “mechanical device” (c.1300), from the Old French engine “skill, wit, cleverness”, from Latin ingenium (“inborn qualities, talent”), similar to “ingenius”; a machine for making or doing something (Boyle’s pneumatical engine, 1658; Papin’s engine for softening bones, 1678); a device that converts energy into mechanical power (18th century); in modern terms, a machine in which power is applied to do work by the conversion of various forms of energy into mechanical force and motion. [1]

Quotes
The following are related quotes:

“Engine, in general, is any mechanical instrument composed of wheels, screws, or pulleys, in order to life, cast, or sustain any weight; or to produce any considerable effect, which cannot so easily be obtained by the bare application of men’s hands, without such help Such as war-like engines, engines to raise water, cranes, etc.”
— John Harris (1705), Lexicon Technicum [6]

“About 6 or 8 years ago my ingenious friend Mr. John Robinson having [contrived] conceived that a fire engine might be made without a lever—by inverting the cylinder and placing it above the mouth of the pit proposed to me to make a model of it which was set about by having never completed and I [being] having at the time ignorant little knowledge of the machine however I always thought the machine might be applied to [more] other as valuable purposes [than] as drawing water.”
— James Watt (1765), entry in notebook [5]

“A perfect thermo-dynamic engine is such that, whatever amount of mechanical effect derived from a certain thermal agency; if an equal amount be spent in working backwards, an equal reverse thermal effect will be produced.”
— William Thomson (1849), “An Account of Carnot’s Theory of the Motive Power of Heat” [4]

“The whole of developments and operations of analysis are now capable of being executed by machinery. As soon as an analytical engine exists, it will necessarily guide the future course of science.”
— Charles Babbage (1864), Life of a Philosopher [3]

See also
● Engine development timeline

References
1. (a) Licker, Mark D. (2003). Dictionary of Engineering. McGraw-Hill.
(b) Engine – Online Etymology Dictionary.
2. Corliss steam engine – Wikipedia.
3. (a) Babbage, Charles. (1864). Life of a Philosopher (pg. 136-37). Publisher.
(b) Bynum, W.F. and Porter, Roy. (2005). Oxford Dictionary of Scientific Quotations (pg. 34). Oxford University Press.
4. (a) Thomson, William. (1849). “An Account of Carnot’s Theory of the Motive Power of Heat; with Numerical Results Deduced from Regnault’s Experiments on Steam”, Transactions of the Edinburgh Royal Society (pgs. 127-203) , xiv.; Annales de Chime, xxxv. 1852; in: Mathematical and Physical Papers (1832-1911), Volume 1 (pg. 119). Publisher.
(b) Bynum, W.F. and Porter, Roy. (2005). Oxford Dictionary of Scientific Quotations (pg. 579). Oxford University Press.
5. (a) Watt, James. (1765). “Entry in Notebook” (words in bracket crossed out by Watt); in: Eric Robinson and Douglas McKie (editors), Partners in Science; Letters of James Watt and Joseph Black (1970) (pg. 434). Publisher.
(b) Bynum, W.F. and Porter, Roy. (2005). Oxford Dictionary of Scientific Quotations (pg. 609). Oxford University Press.
6. Harris John. (1705). ), Lexicon Technicum: a University English Dictionary of Arts and Sciences (§: Eng, pg. #). Publisher.

Further reading
● Ripper, William. (1913). Heat Engines: Being a New Edition of Steam. Longmans, Green, and Co.

External links
● Engine – Wikipedia.