hii 
Date. WHEAL TOWAN. CoNnsOLIDATED MINES. 
1828—April...... 87: millions. |103°7 millions} 57-2 millions} 68:1 millions 
so alle, BGeeios * — , 67°5 a 80:4. 
ROWE UNC do evan 76:1 - 907A ee 61:5 = 73:3 55 
~y  dulhy Soccer 75°83 a5 90:3 ey 65:4 3 717-9 43 
INF EWE 66.50] | SED op OA an Bil) 6 10 Gp 
»  september.} 816 _,, DIB os 62:8) eure ERS op 
Pe OCCODET ee Nl sGleS) 755 92 Ais OPT TESS op 
» November.] 74:2 ,, 88:4) = 60:8)" ;; (CRE ss 
;, December .} 73°6 3 87:7 i 63° 3 751 af 
As the means employed by Grose, and the sharp competition 
which for a time prevailed between his engines and the engine 
which Woolf had removed from Wheal Alfred to the Consolidated 
Mines, formed a theme for keen discussion by all parties interested 
in mines; protective measures were generally adopted at once, 
and the average performance throughout the county immediately 
advanced,t in a manner unequalled in any similar interval of the 
sixty years during which the reports have been continued. For 
four years, however, the engine at heal Towan maintained the 
* A trial made at this period by several Engineers, Captains, Pitmen 
and others afforded for twenty-six hours a mean duty of 87:2 millions per 
bushel (103-9 per cwt.) of coal. Henwood, Edin: Journal of Science, x., p- 
37; Phil: Mag: and Annals, x., p. 102. Taylor, /bid, vii., p. 425. Lean, 
Historical Statement, pp. 59-61. Pole, Cornish Pumping Engine, p. 65. 
During an experiment on the same engine by Mr. (now Sir John) Rennie 
and myself in April 1830 the duty by 
Computation of the load, velocity, and consumption oF) 
fuel amounted to 92°6 millions per bushel or 109-9 + of coal consumed. 
[DEP OW coon do co 00o0 Ds 00d CD dD OOOO OO SD DDODOODC ED 
Computation of the quantity of water delivered by the 
pumps amounted to 83-6 millions per bushel or at hos coal consumed. 
[DSP GWilio coco oooococd UCDO DD ObOO ODDO OUaD DONS ONORNN 
Phil: Mag: and Annals, x., p. 102; Trans: Inst: Civil Engineers, i1., 
p. 58. Ante, p. 44. 
An earlier notice of this experiment was published, by Mr. Taylor, 
from notes furnished by me to Mr. R. J. Neville, then the principal adven- 
turer in Wheal Towan. Phil: Mag: and Annals, vii., p. 425. - 
In 1831 this engine was tried for a third time, when the coal consumed 
was both measured and weighed. 
The result obtained was 86:5 millions per bushel ;—or 
96°9 ” per ton of coal. 
Henwoop, Report of the British Association, vi., Part ii., p. 129; Trans: 
Inst: Civil Engineers, ii., p. 58; Edin: New Phil: Journal, xxvii., p. 50. 
“Tn one engine [at Wheal Towan the lecturer] had succeeded in raising 
‘125-7 million lbs. of water one foot high with one bushel of coal.... The 
‘average performance of the engine is from 70 to 80 millions,” GaLLoway 
(Ex1zaH) Lecture 21st February, 1833. Proceedings of the Plymouth Insti- 
tution, 1813-1833, p. 65. 
+ Lean, Historical Statement, pp. 57,59. Postea, pp. 58, 59. 
D 3 
