Steam-Engincs tJi Cornxaall. 427 



But are all the adventurers in Cornwall likely to be so ig- 

 norant ? and are they not in a situation to have acquired more 

 experience in engines than most other persons? They have 

 witnessed each step of improvement, they have been paities 

 to the strifes and contentions respecting them, and they can 

 certainly tell by their cost-books whether their saving in coal 

 and in money corresponds or not with the calculations of duty 

 which they receive from the agents whom they employ and pay 

 to furnish them with this information ; and they or their ma- 

 nagers can judge whether such agents are competent to the 

 task, and perform it correctly. It has been suggested also, as 

 I hear, that the data are taken in a negligent manner, that 

 pumps are not correctly gauged, that the coal is not measured, 

 and that all is vague and indefinite. Now I have already en- 

 deavoured to show how important it is thought by the owners 

 of these engines to have a very correct account of their duty. 

 I have stated that they pay liberally for such an account, and 

 that their agents at least are competent to judge of the man- 

 ner in which it is furnished by the parties specially appointed 

 for tlie purpose. It is therefore rather too much to suppose 

 gratuitously that the means of obtaining correctness are to- 

 tally neglected. 



I assert, however, that the greatest possible care is taken in 

 all the steps of the process ; and this I will endeavour to ex- 

 plain more fully. The duty of the Cornish engines is taken 

 and computed by Messrs.Thomas and John Lean, who publish 

 separate lists of the engines which they respectively have the 

 charge of; the counters are carefully under lock, and no one 

 has access to them but themselves. At some mines other 

 counters are attached for the inspection of the agents, and at 

 the Consolidated Mines a daily computation of duty is made 

 from them, which is posted up in every engine-house on the 

 concern. The average of these, 1 may observe, is compared 

 with the monthly report, and found generally to coincide as 

 nearly as possible. 



The calibre of the pumps is taken occasionally by the re- 

 porter; and I have been assured by Captain Tiiomas Lean, 

 that he does not rely upon any account given to him, but on 

 his own measurements ; they are subject to some alteration by 

 wear, which is attended to from time lo time. Tlie experi- 

 ment upon Wheal Towan furnishes some evidence on this 

 point; the diameters of the pumps which 1 have given above 

 were taken, I presume, to satisfy Mr. Rennic, and they are 

 stated to eighths of an inch; they agree very nearly wiijj those 

 in the report of March by Mr. Joim Lean. The shortest 

 way, however, of comparing, is by taking the computed weight 

 3 I 2 of 



