.DURHAM AND NORTHUMBERLAND. 225

by Mr. Chapman, whose experience and in-vestigations upon the subject render his opi-nions very valuable to society.

Mr. Chapman estimates that nearly onefourth of the coals won up the shafts aretaken away by screening before they are puton board, some parts of which are used formaking cinders, and other parts for makingmineral tar; but by far the greater quantityremain in large heaps near the mouth of thepit, exclusive of the waste previously madeby hewing the coal underground.

Those heaps which lay on the surface un-dergo a process of decomposition from theeffect of wet, &c., and spontaneously take fire,continuing to burn for a great number of years,and illuminating the country at night in almostall directions.

Mr. Chapman very justly remarks, that thecoal thus wasted would be of the greatestservice for agricultural purposes, by enablingthe farmer to burn lime at a more economicalrate than he can possibly do while excludedfrom the benefits of cheap fuel, and at thesame time obviate a great and increasing in-cumbrance to the soil near the collieries. Toaccomplish this, Mr. Chapman proposes thatthe small coals, upon which he would have the

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