xlviii 
elastic fluids ;* but—in spite of industrious publication by de- 
luded partizans—it never found credit with either philosophers or 
practical men. During a few ensuing years he erected several 
small steam-engines ;> but—in some cases at least—their per- 
formance was not entirely satisfactory.{ About 1812§-1813,|| 
however, he returned to Cornwall,4] and shortly afterwards he was 
appointed to Wheal Abrahum,** Wheal Vor,tt and Wheal Unity, 
at all which he erected (Hornblower’s) engines with two cylinders. 
The first of two engines set up at Wheal Abraham maintained, for 
some years, a very ‘high frequently, indeed the highest—place i in 
* “Mr. Woolf has found, by actual experiment, setting out from the 
‘boiling point of water, or 212°, at which degree steam of water is only 
‘equal to the pressure of the atmosphere, that in order to give it an in- 
“ creased elastic force equal to five pounds the square inch, the temperature 
‘must be raised to about 22732°, when it will have acquired a power to ea- 
““nand itself to five times its volume, still be equal in pressure to the atmos- 
“‘ here, and capable of being applied as such to the working of steam- 
‘engines, .. . and with regard to various other pressures, temperatures, 
‘*and expansive forces of steam . . . as in the following table,”— 
Pp 8 
Pounds per Degrees of Expansi- 
square inch. heat. bility. 
fend \ ( Del ahsk ( Ver? 
S585 hg | 32 | Sor cleo Ses Cues 
aS Ss 6 dao 2304 og 6 8 S) 
al | > 7 Te S 9393 o fo) 7 soo 
ue ge 4 1 lS mang 
£272 8 as ma) | S&S 8 alse 
Boas | D | se. | ac | 238 9 | eas 
SO ws 2 10 Zi jf PaO. ona 10 Se] 
as) 5 PSN oan 7 Has 15 Pe 
SisHx gq 15 a 502 oo a4 Tn 
Se Os | oD eee | oR ess 20 | §83, 
wie 3, > Qo 2 od i = 2 oO 
Sage | 2 | 24 267 a3 a 25 | 23 ais 
gone 0 pests 273 ee ey | BO no 9°6, 
SBes | a | BS am | ee | 35 | gees 
~ ial - S 
BESS | 40 | BR | 282 3B & 40) BSS5 
Grecory, Mechanics, ii., pp. 395-396. Rrzs, Cyclopedia, xxiv., Article, 
Steam- Engine. 
+ Rees, Cyclopedia, xxiv., Article, Steam-Engine, (N). Farey, Phil: 
Mag : and Annals, vili., p. 308. 
+ “T bave been favoured by Mr. George Rennie with some notes of 
“trials made by his father in 1807 upon Woolf's engines at Meux’s Brewery 
‘Cand at Reid’s Distillery, whereby they appear to have been doing much less 
‘“‘ duty than Watt’s engines of the same period.” Pour, Cornish Pumping- 
Engine, p. 55. 
§ Henwood, Hdin: Journal of Science, x., p. 351. 
|| Farey, Phil: Mag: and Annals, vili., p. 308. Pole, Cornish Pump- 
ing-Hngine, p. 55. 
q Not in 1810. Taylor, Records of Mining, i., p. 155. 
** TLean, Historical Statement, p. 15. 
++ Ibid, p. 31. 
