30(5 PATENT RIGHTS. 



Trevithick unfortunately did not take out a patent for that im- 

 provement. The adventurers of two or three mines only had 

 the honesty to pay 100Z. for each mine ; others made use of it . 



without acknowledgment. 



" ED. EDMONDS. 



" PENZANCE, I2th January, 1853." 



Such were the recollections of the family solicitor 

 many years after the events had passed. The cylin- 

 drical high-pressure steam hoiler and engine was really 

 included in the patent of 1802 ; but frequent detail 

 changes, consequent on size and position and local 

 requirements, were made up to 1811, when a perfected 

 form was arrived at, which is still in use. In principle 

 it was unaltered and not materially different in form, 

 but being used for larger engines, looked different. The 

 inventor saw nothing in this difference, but the public 

 did, and in the absence of the only man who could 

 prove their error refused to pay on the plea of its riot 

 being patented. On his return from America he de- 

 manded 1000/. from each of the large Cornish mines, as 

 a settlement in full for all benefits derived from the use 

 of the Trevithick high-pressure steam-boiler. He had 

 proved the weakness of the law years before, when three 

 eminent counsel had given opinions on the 1802 patent, 

 one of them believing the patent good, because the 

 principle contained was new ; two of them feared that 

 similarity of details might invalidate it: 1 so he deter- 

 mined to apply to the Government for remuneration for 

 benefits that might be called national. 



" MR. KD. EDMONDS, "HAYLE, December 20th, 1827. 



" Sir, I send the principal heads of what you will have 

 to put in form to lay before the House. It is very defective ; 

 but you will be assisted by Captain Andrew Vivian, who can 



1 Fee vol. ii , p. 129. 



