Date: 1829
Wheal To wan ceased to work in 1814, and the average con sumption of coals, per month, was in 1813 and 1814, as Mr. William Mitchell has been kind enough to inform me, 9,360 bushels.  The re- working of this mine was undertaken by the present adventurers in 1826; it is now 10 fathom deeper than in 1814, and moreover, the adjoining mines of South Towan, Wheal Charles, and Clifldowns are drained, which was not the case be fore, and the consumption monthly by Captain Grose's engines is but about 2,600 bushels.  In 1814, it may be observed that the average duty of all the engines was about 20 millions, and at the present time, the duty of the engines at Wheal Towan averages 66 millions, and allow ance being made for increased depth and extent, we shall see