liv | 
first place ;* but it ceased to perform, under ordinary circum- 
stances,t the same duty it had performed in 1828. 
2 
* Lean, Historical Statement, pp 61, 87, 93, 94. 
+ In 1831 experiments were made on the best of several engines in 
which various modes of economising the force of dense steam were adopted 
by different engineers. The engines selected for trial were— 
East Crinnis of 76 inches cylinder, erected by Sims, which during the 
year had performed a duty of 64:6 millions ; 
Wheal Towan of 80 inches cylinder, erected by Grose, which during the 
year had performed a duty of 76-6 millions ; 
Binner Downs of 70 inches cylinder, erected by Thomas, which during 
the year had performed a duty of 52: millions; 
The boilers, steam-pipes, steam-nozzles, and cylinders of all three were 
covered with at least sixteen inches in thickness of ashes or saw-dust; and 
this was, in fact, the only protection applied to any part of the engine at 
Hast Crennis ; the cylinder together with its cover and bottom were enclosed 
in a case or jacket, which communicated with the boilers, at Wheal Towan ; 
and flues, from small separate fires, passed beneath the steam-nozzle, over 
the cylinder cover, and wound spirally round the cylinder at Binner Downs. 
These are, perhaps the earliest, if, indeed, they are not the only, Cornish 
trials—save the one experiment made with a single bushel of coal (Wicksteed, 
Trans: Inst: of Civil Engineers, ii., pp. 61-64)—in which all the fuel con- 
sumed was both measured and weighed. At 
Hast Crinnis.. 34 bushels weighed 3,005 lbs , or 88°3 lbs.) per bushel mea- 
Wheal Towan.50 _ ,, ue BOOB dg) gg 1HOOR 55 \ sured from the 
Binner Downs 60 _ ,, 3 BABI oy) gy SBE heap. 
The duty performed amounted at— 
Hast Crinnis .... to 73-9 millions per bushel, or 93°3 per ewt. of Coal ; 
Wheal Towan .. ,, 86:5 a es a O19) + 3 
Binner Downs .. ,, 73:8 89:2 
At Wheal Towan each bushel of "coal evaporated 16- 91; each ewt. 18: 92 cubic 
feet of water. 
Taking the coal, grease, and oil consumed at their market prices, the en- 
gine at 
East Crinnis lifted ...... see. 870 tons . 
Wiesel! LOW 35" congcanqoe LAUSD 54) ee date) Guainaiaste 
Binner, Downs 5, ...2...--- 1,006 ,, S- 
During all these experiments diagrams were frequently taken with the 
Indicator ; the pressure of the steam used, the temperature of the conden- 
sing-water and of the hot-well, together with many other particulars, were 
all frequently and carefully noted 
Henwoop, Hdin: Journal of Science, x., p. 41. Report of the Brit: Asso- 
ciation, vi., Part ii., p. 129; Trans: Inst: Civil Engineers, ii., pp. 49-60; Pl. 
iv., Fig. 4-11; Hdin: New Phil: Journal, xxvii., pp 42-52; Reports of the 
Royal Institution of Cornwall, xx., p. 20. Parkes, Trans: Inst: Civil Engi- 
neers, 1i., pp. 257-294, Pl. ix., x. Combes, L’Kaxploitation des Mines, iii., pp. 
542, 562, Pl. lxii, Fig. 4, 5. 
‘“Myr,. Henwood’s . . . Series of Indicator diagrams.... . are the 
earliest on record.” Envs, Trans : Inst: Cwil Engineers, ii1., p. 455. 
From this time forward the bushel of Welsh coal has been taken to 
weigh 94 lbs. 
Enys, Reports of the Royal Corn: Pol: Society, v., p. 72. Wicksteed, 
Trans: Inst: Cwil: Engineers, ii., p. 61. Lean, Historical Statement, pp. 99, 
135-138, 140. Husband, Pr oceedings of the Inst: Civil Engineers, xxiii., p. 79. 
