24 VARIOUS INVENTIONS. 



measure on the time it will take in doing. If it takes eight 

 years it would be 5001. a year for you (according to Mr. Giddy's 

 calculation). 



" Your well-wisher, 



" HENRY HARVEY. 



" MR. RD. TREVITHICK, Cumborne" 



Mr. Harvey knew Trevithick's weakness in money 

 matters. Eennie had been employed to report on the 

 proposed Plymouth Breakwater, and in 1811 was de- 

 sired by Lord Melville, the head of the Admiralty, to 

 proceed with the work. "The price paid in 1812 for 

 taking. and depositing rubble in the breakwater was 

 2. 9d. per ton ; it was afterwards reduced to Is. per 

 ton. A piece of ground was purchased from the Duke 

 of Bedford at Oreston, up the Catwater, containing 



25 acres of limestone, well adapted for the purposes of 

 the work ; and steps were taken to open out the quarry, 

 to lay down railways to the wharves, to erect cranes." 1 

 The idea of the plan to be followed in conveying stone 

 with greater economy and dispatch than was contem- 

 plated by Rennie, originated with Trevithick, while 

 the former received the credit and the pay, as he before 

 had done with the steam-dredger. 



[Rough draft.] 



" MR. FOX, Jun., " CAMBOHNE, January 2Sth, 1813. 



"Sir, Since I was at Roskrow I have been making 

 trial on boring lumps of Plymouth limestone at Hayle Foundry, 

 and find that I can bore holes five times as fast with a borer 

 turned round than by a blow or jumping-down in the usual way, 

 and the edge of the boring bit was scarcely worn or injured by 

 grinding against the stone, as might have been expected. I 

 think the engine that is preparing for this purpose will bore ten 



Lives of the Engineers,' by Smiles, vol. ii., p. 260. 



