the boiler cylinder and piston

Boiler, cylinder and piston: AD 1704-1712
Two metalworkers, Thomas Newcomen, and John Calley, are making good progress in some potentially very profitable experiments. They know the high cost of the horse-driven pumps that raise water from the copper and tin mines. So they are working on a steam pump. Though unaware of this, they are combining two elements pioneered separately, Papin's piston and Savery's separation of the boiler from the cylinder.
In Newcomen's engine the piston is attached by an iron chain to one end of a beam which seesaws on a central pivot. At the other end of the beam another chain leads down to the water-pumping mechanism. Steam released from the boiler into the cylinder pushes up the piston. When the cylinder is full of steam cold water poured on the outside condenses the steam and creates the vacuum. But in this case, instead of directly sucking up water, the vacuum causes the piston to descend in the cylinder. This activates the pump at the end.
As so often in the advance of science and technology, an accident provides Newcomen with the refinement which brings his pump up to an economic speed. A flaw develops in one of the seams of his cylinder. As a result some cold water, intended only to flow down the outside, gets into the cylinder when it is full of steam. It creates a vacuum so rapid and so powerful that it snaps the chain attaching the piston to the beam. With this event another lasting feature of the steam engine is discovered. In all Newcomen's developed engines, which soon start work in England's mines, the steam is condensed by a jet of cold water injected into the cylinder.
The first of Newcomen's working engines is installed in 1712. It operates successfully for thirty years, as the first of many in the mining districts of Britain. Even with Newcomen's improvements, these machines are suitable only for the slow relentless work of pumping in the mines.