li 
set up by Woolf at Wheal Alfred in 1825—and had there per- 
formed from 30°8* to 41:9*F per bushel (36-7 to 51:1 per -cwt.) 
—ceased to work there in 1826; was removed by him to the 
Consolidated Mines in 1827, and—by adopting the means which 
had been already so successfully adopted at Wheal Hope and 
Wheal Towan§—attained, (during three months,) a higher duty 
than any other engine in Cornwall. The following columns show 
the performance of these excellent engines during the ay pro- 
gress|| of protection by non-conductors of heat ;— 
WHEAL TOWAN. CONSOLIDATED MINES. 
Wilson’s Engine,—Grose Wheal Fortune (Woolf’s) Engine, 
DATE. Engineer. Woolf Engineer. 
Per (94 lb.) Per hundred Per (94 1b.) Per hundred 
bushel. weight. bushel. weight. 
1827—January . ..| 48-9 millions] 58°3 millions} —— — 
» February ..} 51:8 5 61:7 59 —— — 
” March eoce 53°5 9 63°7 ” ar eae ae 
Pea AT tosreies Gil Gian. TBO a —— — 
oo WEN, coeco8 60°6 us 72:2 2 — — 
UMC siaeronts Giles, CEH op TF Sar 
op Owihy Sooccs 6272 iene TAL 59 — — 
» August ....) 61:7 a 73°5 56 —. — 
»  September.} 60:1 ,, TAI gg — — 
October Olcan an, 73° 9» 63-7 millions| 75:9 millions | 
,5, November .} 56:1 Ps 66°8 90 67° 3 79:8 35 
» December .] 57:7 ,, OY og PES | U4kee a6 
1828—January...} 64:4 3 76°7 50 59°2 % 70°5 5 
», February ..| 73° a 87° 99 62-9 a 75° “ 
ee Marchinvaiece:2tcn 4.5 100: an 62,3 TAD) aa 
* Henwood, Edin: Journal of Science, x., p. 48. 
+ Taylor, Records of Mining, i., p. 158. Lean, Historical Statement, p. 56. 
Farey states 42°6. Phil: Mag: and Annals, viii., p. 312. 
t Carne, Cornwall Geol: Trans: iii., pp. 348, 351-353. Henwood, Phil: 
Mag: and Annals, vii., p. 324. Farey, Ibid, viii., p. 313. Taylor, Records 
of Mining, i., p. 158; Quarterly Mining Review, ii., p. 44; Annales des 
Mines, 3me Série, ii., p. 64. 
This engine—probably by a merely clerical error—is represented as 
still at work on Wheal Alfred throughout 1828; whereas it had been already 
removed to the Consolidated Mines, “and, in fact, its performance there was 
recorded, in 1827. Lean, Historical Statement, pp. 57, 58, 64, 69. 
§ Farey, Phil: Mag: and Annals, viii., p. 813. 
|| Phil: Mag: and Annals, ii., p. 309. Henwood, Edin: Journal of 
Science, x., pp. 46, 48; Phil: Mag: and Annals, vii., pp. 101, 102. Taylor, 
Records Wi Mining, i., pp. 158, 159; Quarterly Mining Review, v., pp. 44, 46. 
Annales des Mines, 3me Série, ii., pp. 64, 65. Lean, Historical Records, pp. 
57-62, 69, 87, 93-94. : 
q At this time an experiment conducted by Engineers, Captains, and 
Pitmen of other mines gave during twenty-six hours and a half an average 
duty of 63°6 millions per bushel (75:8 per ewt.) Henwood, Hdin: Journal 
of Science, x., p. 101. Taylor, Records of Mining, i., p.159. Lean, His. 
torical Statement, pp. 58, 59. Pole, Cornish Pumping Engine, p. 64. 
