Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/66



It may be desirable to give an estimate of the quantity of coal that is annually received from the Coal-field. The annual shipment of coal for a series of years from the Tyne, the Wear, Hartley and Blyth will be found in the appendix, No. 2. From these it appears that the quantity shipped

But there are no precise data for calculating the home consumption of the two counties. About thirty years ago a practice was adopted at the pits, where the coal was of a fragile nature, of erecting screens to separate the small from the sounder coal. This system is now become universal, and immense heaps of coal are thus raised at the mouths of the pits. These soon take fire from the heat of the decomposing pyrites, and not less than 100,000 chaldrons are thus annually destroyed on the Tyne and nearly an equal quantity on the Wear. It is greatly to be desired that some use should be found for the small coal in order to prevent so great a waste.