56 Mr. N. J. Winch on the Geology of 



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 



From the port of Newcastle, in the year 1813, was of Newcastle? cmo „„ a 



chaldrons 1 * j 



From the port of Sunderland 330,967 



From Hartley and Blyth, in the year 1811 53,958 



tTIic quantity shipped annually from the four ports being about . . 983,698 

 The quantity vended from 35 Landsale pits in the county of Durham"! -o 4 aq 



was in (he year 1808 J 



The quantity consumed in Newcastle, Sunderland, North ancU 



South Shields, Hartley and Blyth was computed by Dr. Macnabi V 190,000 

 in the year 1801, at J 



But there are no precise data for calculating the home consump- 

 tion of the two counties. About thirty years ago a practice was 

 adopted at the pits, where the coal was of a fragile nature, of erect- 

 ing 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. 



* The Newcastle chaldron = 53 cwts. or y of the London chaldron. 

 + It appears from the table given in the Appendix, (No. 2.) that in the year 1813, 

 970,901 London chaldrons of coal were imported into London. Deducting from these the 

 50,000 chaldrons brought by canals from the midland counties, there will remain 920.901 

 London chaldrons =. 491,147 Newcastle chaldrons of coal imported by sea into London. 

 % See his Tract on the Coal trade. 

 || Beneath the heaps that have taken lire, a bed of blackish brown scoria is forroefcU 

 which greatly resembles basalt, and is used for mending the roads. 



