THE CORNISH PUMPING ENGINE. 
27 
noticed by Mr. Watt, who paid a visit to the mine on purpose to examine and 
experiment upon it. He pronounced it perfect, and is reported to have declared 
that no further improvement could he expected! 53 little imagining that in less than 
half a century this amount would be increased four or five-fold. 
The advantage of Watt’s improvements in deepening the mines and extending the 
mining operations generally was very great, and the demand for the engines, their 
large size, and the great amount of the saving, consequent upon the high price of 
coal, rendered this district, as Mr. Watt had predicted in 1778, almost a mine of 
wealth to the proprietors of the patent, up to the time of its expiration. They are 
said to have received from the county nearly £180,000 for coal savings alone, 
exclusive of the profits of manufacture. 54 
39. Smeaton, whose improvements were introduced but a very short time before 
those of Watt, became desirous of extending the use of the latter as soon as he 
heard of their great success; but not being altogether satisfied of the accuracy of 
the reports of the large increase of duty, he undertook experiments, about 1778, on 
two of Watt’s engines; one at Birmingham, the duty of which he found to be about 
eighteen millions; the other at Hull, which gave about half a million more. He 
came to the conclusion that Watt’s engines performed, on an average, double the 
duty of the atmospheric engine as improved by himself. 
Smeaton had at this date erected many large engines on his improved construc 
tion, and had altered many more; hence, while he was anxious to gain for them 
some advantage from Watt’s inventions, he naturally wished to avoid the expense of 
completely remodelling them; and he accordingly made proposals to the patentees 
for permission to adapt the separate condenser to the atmospheric engine. 55 
good Newcastle or Swansea coals in Mr. Watt’s reciprocating engine, working more or less expansively, 
was found, by the accounts kept at the Cornish mines, to raise from 24 to 32 millions of lbs. of water one 
foot high ; the greater or less effect depending upon the state of the engine, its size and rate of working, 
and upon the quality of the coal.” This high rate of duty does not agree with any of the data we are at 
present in possession of, and if the Cornish accounts alluded to in the quotation were not overstated, 
they are now no longer to be found. Those mentioned in the text appear to be the only authenticated 
reports of the duty of Watt’s engines in Cornwall. 
53 Taylor’s Records of Mining, page 154. 
54 Report of Polytechnic Society of Cornwall, 1837, page 71, and 1838, page 16. 
65 The atmospheric engine, with a separate condenser, has from its simplicity been often recommended, 
and sometimes used, in cases where fuel is cheap, as at the mouths of coal mines, &c. ; see Tredgold’s 
Treatise, page 97. M. De Pamhour, in his * New Theory of the Steam Engine,’ has given calculations 
respecting such an engine, as has also Mr. Enys, in the ‘ Transactions of the Institution of Civil Engineers,’ 
vol. iii. page 465. A patent was taken out by the late Mr. Samuel Seaward but a short time ago for a 
similar arrangement for steam vessels.