1864. | Hout on the Coal Resources of Great Britain. 27 
lower Carboniferous series, and is therefore of greater antiquity than. 
that of England. It occupies the broad valley stretching from the 
Firth of Forth te the Firth of Clyde, and is bounded on the north by 
the frontiers of the Highlands, and on the south, by the hilly and 
wild tract which gives birth to the sources of the Tweed. The coal- 
seams are often interrupted by the intrusion of igneous rocks, and in 
some places, the older Carboniferous and Devonian formations rise to 
the surface, and terminate the continuity of the beds. There is docu- 
mentary evidence to show that coal was worked in Scotland from at 
least the fourteenth century,* and the Celtic name for the mineral is still 
preserved in that of a little tarn, called Lough Glo. The total area of 
workable coal equals 1,720 square miles, and the total available supply 
of coal to a depth of 4,000 feet, amounts to 25,300 millions of tons. 
The quantity raised in 1861, was 11,081,000 tons from 424 col- 
lieries.t In this is included the double coal-trough of the Lothians 
—the resources of which were calculated with much labour by Mr. 
Milne-Hulme and Mr. 8. Nicol, several years ago. It will be seen 
from the above estimates, that there is coal enough to last at the present 
rate of consumption for about 2,000 years. 
Eastern Coa-GRrovr. 
The Great Northern Coal-ficld.—The resources of this district have 
been more fully illustrated than those of any other coal-field in England. 
No less than six distinct estimates having been made, and they all come 
to very nearly the same conclusion regarding the available quantity 
of coal at the time specified by each. 
The coal-field extends from the mouth of the Coquet, on the 
north, to that of the Tyne on the south, a distance of fifty miles. The 
strata dip generally eastward, and are ultimately concealed beneath 
the table-land of the Magnesian Limestone, which is now penetrated 
by shafts in search of the subordinate coal-beds. The actual coal- 
field has an area of 460 square miles, but to this we must add the area 
overspread by the Magnesian Limestone, and other formations of more 
recent age—that is, 225 square miles—making in all 685 miles, and 
containing about 7,200 millions of tons of available coal. This coal- 
field has from the infancy of mining been one of the greatest pro- 
ducers; and from its store the Metropolis of the Empire has prin- 
cipally been supplied. The consumption is still steadily increasing, 
* AMei Sylvii Opera, p. 443. 
+ ‘Coal-fields of Great Britain,’ 2nd edit. p.179. I must here apologize to 
the reader for quoting myself, which I do for the simple reason that there is 
no other authority extant for the resources of all the British Coal-fields, though 
there are for a few special ones which shall be stated. The calculations contained 
in my work were made with much care, and have been used by Sir W. Armstrong, 
President of the British Association. I may here state, in order to avoid the 
appearance of dogmatism, that in dealing with so large a question as the number 
of tons of coal in any of our coal-fields, the figures do not pretend to be more than 
close approximations to the reality, but it would be a useless repetition to place 
before each group of figures such words as “ about,” “approximately,” “ nearly,” 
&e., which the reader is requested mentally to introduce for himself. 
} Hunt's ‘Mineral Statistics of Great Britain’ for 1861. 
