428 Mr. John Taylor on the Duty of 



of water by each method, which, calculated for Mr. Rennie's 



experiment, was VOjTS* pounds. 



Stated in duty paper for March 70,60.5 

 So that taking diameters and lengths together, they were found 

 ratlier to exceed the printed account, but differ only by 129 

 pounds in the whole. 



Those who are acquainted with the management of the mines 

 know that the coal is very accurately measured to each engine; 

 both that the duty of the engine may be ascertained, and that 

 the drawback allowed by the Custom-House may be obtained, 

 which is granted on the oath of the parties that the measure- 

 ments are correct. 



I will explain with how much precision this is conducted 

 at the Consolidated Mines, In each engine-house a paper, 

 printed in columns to serve for one month, is placed, called 

 The Engine-men and Coal-measurers' List. The engine-men 

 are required to place in the column. No. 1, a statement of the 

 quantity of coal wanted for the next 24 hours, which is to be 

 done between the hours of 7 and 8 in the morning for every 

 respective day of the month, and where the coal-measurer 

 may refer to know the quantity required. This person de- 

 livers the quantity required daily, by accurate measurement, 

 and places the account of what he actually delivers in column, 

 No. 2; and further, one of the engine-men on duty must see 

 the coal delivered into the sheds, keep an account of the mea- 

 surement, and certify the quantity by marking it in column, 

 No. 3. A penalty is imposed for any neglect of this order. 



The engine-men, being to a certain extent responsible for 

 the duty of their engine, ought to see, as they do by this regula- 

 tion, that they have their proper quantity of coal ; and it is the 

 express purpose of the coal-measurer's office that no more than 

 what is accurately registered be delivered. 



But here, again, the experiment on Wheal Towan engine 

 may be quoted; the duty was found to be 92,331,899. The 

 experiment in 1828 gave a result of 87,000,000, and the aver- 

 age duty of 12 reports published last year was 76,234,307. 

 Now as the performance of any engine under experiment will 

 be free from those stoppages or hindrances which we know 

 diminish duty, and which cannot be avoided in the work of a 

 month, we may expect that what would be found in the one 

 case would exceed that of the other; and so it proves to be. 

 Now as doubtless Mr. Rennie, and the gentlemen who were 

 with him, took care to see the coal properly measured and ap- 

 plied, it follows that the measurement for the 12 months, of 

 which the duty was reported, was very nearly correct also. 



Wheal Towan is a mine which was in full work previous to 



1814, 



