Steam-Engines m Corrmall. tSo 



tain King, superintendant of the packets at Falmouth, and in 

 consequence Mr. Rennie has been desired to investigate the 

 facts. 



This gentleman lately visited Cornwall, and selected for ex- 

 periment Wilson's engine at Wheal Towan, erected by Capt. 

 Samuel Grose, which has for two years past stood highest in the 

 monthly reports, and which is so justly celebrated for its per- 

 formance and for its general excellence as a pumping-engine. 

 The following are the particulars and dimensions of the 

 most important parts, as noted by parties present at the mine 

 at the time of the experiment. 



Cylinder 80 inches diameter. 

 Length of stroke in the cylinder 10 feet, 

 in the pumps 8 feet. 

 Usual rate of working about 6^ strokes per minute. 

 Draws 5 lifts of pumps of the following lengths and 

 diameters. Heights. Diameters. Weight. 



Fath. Ft. In. Inches. lbs. 



House lift 44 1 9 13 15313 



Tye lift 43 5 9 ISJ 22656 



Rose lift 32 5 9 16^ 17525 



Crown hft 18 5 8 17j 12381 



Puppy lift 9 4 2 12 2856 



149 5 1 70731 



The water contained in this column is 1131*7 cubic feet; 

 weight 70731 pounds; being at the rate of 11*15 pounds per 

 square inch of the piston. 



During the experiment made by Mr. Rennie, the engine 

 made 979 strokes and consumed 6 bushels of coal, which 

 gives for duty, according to the preceding data, 92,327,000 

 pounds lifted one foot by each bushel. 



A former experiment on this same engine was made in 1828, 

 in the presence of several mine agents and engineers, to which 

 I alluded in my paper on the duty of steam-engines, pub- 

 lished in the " Records of Mining*," and in which the result 

 was 87,210,000 pounds lifted one foot by each bushel. I find 

 that the duty reported monthly in the printed duty papers for 

 1829, is on an average 76,234,307; and it was 77,290,000 in 

 the preceding year, as appears from the statements in the pub- 

 lication to which I have referred. 



It is satisfactory to perceive that at length this subject seems 

 likely to receive the attention, and undergo the investigation 

 it deserves. The facts have been long before the public, but 

 they have been much controverted, and ratiier treated as the 

 statements of visionary or iuterested persons, than as substan- 

 • Murray, 1829. Phil. Ma;?, aiul Annals, vol. v. p. 297 

 N. S. Vol. 7. No. 42. June 1830. 3 I live 



