POLE STEAM-ENGINE. 109 



" TREVINCE, near TRURO, 

 " DEAR SlR, 5fA January, 1853. 



" I am favoured with your letter of the 31st ult., enclosing 

 also one from Mr. F. Trevithick, of the 24th idem, and have 

 much pleasure in complying with your joint request to the best 

 of my ability. I was well acquainted with the late Mr. Kd. 

 Trevithick, having had frequent occasion to meet him on busi- 

 ness and to consult him professionally; and I am gratified in 

 having the present opportunity of bearing testimony to his dis- 

 tinguished abilities, and to the high estimation in which the 

 first Cornish engineers of the day then regarded him. I need 

 scarcely say that time has not lessened the desire in this county 

 especially to do him justice. As a man of inventive mechanical 

 genius, few, if any, have surpassed him, and Cornwall may well 

 be proud of so illustrious a son. 



" At this distance of time I can scarcely speak with sufficient 

 exactness for your purpose of the numerous ingenious and valu- 

 able mechanical contrivances for which we are indebted to him, 

 but in reference to his great improvements in the steam-engine 

 I have a more particular recollection, and can confidently affirm 

 that he was the first to introduce the high-pressure principle of 

 working, thus establishing a way to the 'present high state 

 of efficiency of the steam-engine, and forming a new era in the 

 history of steam-power. To the use of high-pressure steam, in 

 conjunction with the cylindrical boiler, also invented by Mr. 

 Trevithick, I have no hesitation in saying that the greatly- 

 increased duty of our Cornish pumping engines, since the time 

 of Watt, is mainly owing; and when it is recollected that the 

 working power now attained amounts to double or treble that 

 of the old Boulton and Watt engine, it will be at once seen that 

 it is impossible to over-estimate the benefit conferred, either 

 directly or indirectly, by the late Mr. Trevithick, on the mines 

 of this county. The cylindrical boiler above referred to effected 

 a saving of at least one-third in the quantity of coal previously 

 required; and in the year 1812 I remember our house at Scor- 

 rier paying Mr. Trevithick the sum of 3001. as an acknowledg- 

 ment of the benefits received by us in our mines from this 

 source alone. Mr. Trevithick's subsequent absence from the 



