[Copy] Agreement between Richard Trevithick of Penzance in Cornwall, engineer ... and William Sims the younger of Gwennap in the same County, engineer. 1816 Oct 18. [2p. on 1 leaf. Trevithick sells to Sims a half share in the benefits from Devon and Cornwall of the patent dated 1815 Jun 6 [no.3922, improvements to steam engines etc.] Price £200 (plus £50 from future profits of Wheal Chance mine engine); arrangements for administration of the agreement while Trevithick is abroad]