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annually in tlie United Kingdom must have been very small, 
as compared with our present “ output” He has furnished 
us with the means of roughly estimating the relation which 
the production of the two periods bear to each other, espe- 
cially so far as the Newcastle coal-field is concerned. 
The consumption of coal in London 900,000 chaldrons. 
Sent coastwise (for consumption in other towns) 700,000 „ 
Sent for Foreign consumption 250,000 „ 
Consumed at Newcastle, Shields, and Sunderland 450,000 „ 
Total consumption of coal from the rivers Tyne and Wear 2,300,000 ,, 
The number of tons in the above quantity, taking the 
chaldron at 27 cwt., is 3,100,000. 
In 1864 the gross produce sold from, and used at, the 
collieries of Northumberland and Durham, was 23,284,367 
tons, or nearly eight times the quantity given as the produce 
of those collieries when Williams wrote. But a more reliable 
return given by Dr. Millar in the edition of this work pub- 
lished in 1810, shows that Williams's estimate was in excess 
of the truth. From this table we learn, that in each of the 
four years from 1802 to 1805, both inclusive, not more than 
800,000 tons were sent “ coastwise, over sea,” and to “ planta- 
tions ” (our colonies). Whereas in 1864, the Great Northern 
coal-field sent 
Coals to Foreign countries ............. 4,104,484 tons. 
Coke ( estimated as coal ) to Foreign countries 448,362 „ 
Coals sent coastwise 6,188,026 „ 
Coke ( estimated as coal) sent coastwise 46,032 „ 
10,782,904 „ 
To make our comparison correctly, we must deduct 
the quantity brought within the London district 
— as the quantities sent to London are not in- 
cluded in the 800,000 tons 2,927,176 „ 
7,855,728 „ 
Thus we learn that the increase has been more than ninefold 
in the exportation of coal from the Northern coal ports in 
sixty years, and this has been considerably exceeded in several 
other of our large coal-fields. 
When Williams expressed his fears that the coal-fields of 
Great Britain were being rapidly exhausted, they were not • 
producing more than nine millions and a half tons of coals per 
annum. In the year when Sir William Armstrong spoke. 
