Mem[orandum] for Capt. Trevithick ab[out] Boilers, 1827 Dec. 4p. on 1 leaf. [Draft of a statement of the benefits to the nation resulting from Trevithick's inventions, including a quantitative estimate of the savings made by the introduction of high-pressure steam engines into Cornish mines (Poldice, Consolidated, Dolcoath).]