"Before Mr. Trevithick went abroad he sold half the patent right to William Sims, our engineer, who very strongly recommended that two of the engines at the United Mines should be altered to what he considered his patent principle, but the alterations proved very inferior to his expectations, and to this circumstance I attribute much of the objections in question. Mr. Henry Harvey has perhaps told you who the partners are in the patent, and when you next come into this county I shall be much pleased to wait on you at Tredrea that you may hear the whole of the case; and though the United Mines adventurers are far from being a united body, I am very sure my sons, who are their managers, are desirous to recommend what appears to them right, and they will with myself be obliged for your opinion after you have heard the whole matter on both sides. "Dear Sir, "Yours very sincerely, "JNO. WILLIAMS. "DAVIES GILBERT, Esq., M.P." The opinion of Mr. Williams' elder son, Michael, has been given.[150] Some of the family were quakers. No further money payment for the saving of fuel followed this carefully civil note, until Trevithick, on his return from America, called at Scorrier House in a very threatening attitude on 31st October, 1827, when Mr. Williams, sen., said his reason for not continuing the payment was from his belief that the term of the patent had expired. Then came the following lawyer's letter:-- [Footnote 150: See letter from Mr. Michael Williams, vol. ii., p. 109.] "SIR, "PENZANCE, _7th November, 1827_. "I was at Captain Trevithick's yesterday, who observed to me he saw you at Scorrier a few days ago, and requested you would be good enough to settle the arrears on the savings on some of the engines in the mines for which you acted, none having been paid for a year or two, when you stated that the payment had been discontinued on account of the patent having expired. I find on a reference to the patent that it will not expire till May, 1830. "I am, Sir, "Your obedient servant, "RD. EDMONDS. "JOHN WILLIAMS, Esq., _Scorrier_." "SIR, "HAYLE, _January 24th, 1828_. "Yesterday I called on Mr. Williams, and after a long dispute brought the old man to agree to pay me 150_l._ on giving him an indemnification in full from all demands on Treskerby and Wheal Chance Mines in future. He requested that you should make out this indemnification. I could not possibly get them to pay more, and thought it most prudent to accept their offer rather than risk a lawsuit with them. "I remain, Sir, "Your obedient servant, "RICHARD TREVITHICK. "RD. EDMONDS, Esq.