MARINE STEAM-ENGINES. 371 



to reduce the speed. Four months prior to the date of 

 this letter he had sent a written offer to the Common 

 Council of the city of London, offering to provide 

 engines to discharge all coal-ships for the saving he 

 would effect in six months, or he would supply an 

 engine and boxes complete for 100 guineas. He at the 

 same time suggested that in place of the baskets holding 

 1 bushel, iron boxes on wheels, holding 4 bushels, with 

 a spring steelyard attached, should be used with his 

 steam-engine, giving the exact weight without delay. 

 He seems to have forgotten his nautical labourer 

 patented twenty years before ; 1 but yet reproduced 

 something very similar. 



Every trading vessel was recommended to carry at 

 least a 12-cwt. high-pressure steam-puffer engine, suit- 

 able for warping, pumping, and discharging cargo; 

 but a 30-cwt. engine, not occupying more room than 

 a caboose, would in addition cook for the crew, and 

 propel the vessel at three or four miles an hour. 



Two iron paddles, like the duck's feet described to 

 his Binner Downs friends many years before, 2 were 

 to be fixed on an iron shaft across the stern of the 

 vessel, receiving from the engine a motion like a 

 pendulum. Each duck's foot was an iron plate 4. feet 

 deep and 3 feet wide, turning partly round on its iron 

 leg, to which it was attached as a vane, about 1 foot of 

 its width on one side of its leg, and 2 feet on the other 

 side ; when the leg and foot were drawn toward the 

 vessel, the foot, turning on its leg as a centre, exposed 

 its edge only to the water ; on the reverse movement, 

 the longer side like a vane turned round until its flat 

 was opposed to the water, in which position it was kept 



1 Sec vol. i., p. 325, and patent, 1809, vol. i., p. 302. 



2 See Mr. Newton's letter, vol. i., p. 312. 



