What I say here is not to give room for believing, that Mr. Savery, who has since published this invention at London, is not actually the inventor. I… - Denis Papin

Turning a small surface of water into vapour by fire, applied to the bottom of the cylinder that contains it; which vapour forces up the plug (or piston) in the cylinder to a considerable height, and which, as the vapour condenses, (as the water cools when taken from the fire,) descends again by air's pressure, and is applied to raise water out of the mine.

By another way, therefore, I endeavoured to attain the same end; and since it is a property of water that a small quantity of it, converted into steam by the force of heat, has an elastic force like that of the air, but, when cold supervenes, is again resolved into water, so that no trace of the said elastic force remains; I felt confident that machines might be constructed wherein water, by means of no very intense heat, and at small cost, might produce that perfect vacuum which had failed to be obtained by aid of gunpowder. But of the various constructions which can be contrived for this purpose, the following seemed to me to be the most suitable.

In what manner that power can be applied to draw water or ore from mines, to discharge iron bullets to a great distance, to propel ships against the wind, and to a multitude of other similar purposes, it would be too long here to detail; but each individual, according to the particular occasion, must select the construction of machinery appropriate to his purpose.