Strong Steam, Weak Patents, or, the Myth of Watt’s Innovation-Blocking Monopoly, Exploded

James Watt's 1769 patent is widely supposed to have stood in the way of the development of high-pressure steam technology until it finally expired in 1800. We dispute this popular claim. We show that, although it is true that high-pressure steam technology developed only after the expiration of Watt's patent, the delay was due to factors other than that patent itself, including the widely-held opinion that high-pressure engines were excessively risky. Indeed, Watt's monopoly rights may actually have hastened the development of the high-pressure steam engine, by inspiring Richard Trevithick to revive a supposedly obsolete technology so as to invent around them