112 POLE STEAM-ENGINE. 



In 1800, Woolf, who had been a mine carpenter, 

 went to London with the first high-pressure steam- 

 engine which Trevithick had sent beyond the limits 

 of Cornwall 1 probably to Meux's brewery, 2 for he was 

 there in 1803, and in the receipt of 30. a year from 

 Trevithick as engine-fireman. From the date of Woolf 's 

 patent in 1804, his pay from Trevithick ceased, and 

 with it their friendship. Trevithick used to say, " Woolf 

 is a shabby fellow." 



Patents sprang up like mushrooms after Trevithick 

 had so liberally cast forth the seeds of the high-pres- 

 sure engine, making the security, or even the form of 

 a patent, a doubtful matter. The perfecting of expan- 

 sive high-pressure engines was like the boiler, the result 

 of years of trial. When matured in 1816 it saved Corn- 

 wall and the world one-half of the coal that before had 

 been consumed in low-pressure steam-engines. Every 

 engineer became, more or less, an expansive worker, 

 and Trevithick's saving of hundreds of thousands of 

 pounds annually to the general public, gave to him 

 little or no reward. 



At the period of those high-pressure pole-engine 

 experiments, Trevithick had devoted twenty years of 

 constant labour to the improvement and extended use 

 of the steam-engine, causing it to assume every variety 

 of form except that of the Watt patent engine, an ap- 

 proach to which was unusual, as evidenced in the high- 

 pressure steam Kensington model of 1796, without 

 beam, parallel motion, air-pump, or condenser, having 

 no one portion either in principle or detail similar to 

 the Watt engine, being portable and not requiring 

 condensing water, with single and double cylinders, 



1 See Trevithick's account-book, yol. i., p. 90. 



2 Captain John Vivian's recollections, vol. i., p. 142. 



