The stand-alone boiler by Trevithick

 

Trevithick is mostly known for his invention of the first steam-locomotive. But before that he tried to persuade Watt to use higher steam-pressures for his engines. High at that time is a respectable 3 bar.

He even presented a design for such a boiler, but Watt refused, too afraid of steam-explosions. It is then that Trevithick decided to swap to locomotives. It is the end of the 18th century then.

The boiler is round, a perfect form for high pressures, and has an internal firetube.

Many features of this boiler we will see back in the later developed Cornish-boilers. The design of Trevithick was far ahead of his time and of great importance and inspiration to his successors. A surviving example of his boiler can still be found in the Science Mueum in London.