1698, and a very broad patent. Thomas Savery patented his engine for "raising water by the impellent force of fire" in 1698 and published The Miner's Friend setting out its use. Parliament later extended the patent's life by statute, and its wording was wide enough to cover essentially any engine raising water by fire. That single legal fact shaped British engine building for a generation.

Newcomen worked under it. Thomas Newcomen's atmospheric engine of 1712 is a different and far better machine — it has a piston, a beam, and separates the water being pumped from the steam doing the work — but it fell inside Savery's patent, so Newcomen never held a patent of his own and worked in partnership with the Savery interest. The commonly repeated "Newcomen's patent" is a myth, and it is worth correcting whenever the story is told.

Why the Miner's Friend was a poor friend to miners. The suction stroke is capped by atmospheric pressure at around ten metres in theory and less in practice. Anything deeper had to be lifted by steam pressure directly on the water surface, which meant boiler pressures the metallurgy of 1700 could not safely hold. Savery engines burst. They were also thermally wasteful, because every cycle heated and cooled the same vessel. They found real use pumping water in waterworks and on a modest scale, not clearing deep mines.

What it contributed anyway. Savery's machine is the first steam engine sold as a product rather than demonstrated as a curiosity, and it established the central move that the whole eighteenth century built on: condense steam, get a vacuum, let the atmosphere do the work. Newcomen put a piston in that vacuum. Watt then noticed that condensing in the working cylinder wastes most of the heat, and put the condenser somewhere else. Each step is a direct answer to a flaw in the one before, and the chain starts here.

Engines

Blueprints (3)

Rotative Beam Engine

Centrifugal Governor

Savery's Miner's Friend