506 F. H. Hatch — The Iron Ore Supplies of the World. 



headings of ore to be got (1) by open-cast work and (2) by 

 underground mining, from which I have made a deduction for the 

 ore won during the years 1917-19. 



In addition, 26 million tons are assigned to the Westbury 

 (Corallian) ironstone, and 10 million to the Eaasay ironstone, neither 

 of which are at present being worked as a source of iron. This brings 

 the total for the Jurassic ironstones to 2,680 million. It is not claimed 

 that these figures are estimates of actually merchantable ore. It is 

 possible that much of the low-grade ore that it is now found profitable 

 to work in open quarries will not constitute an economic proposition 

 when mining has to be resorted to. 



The reserves of clay -ironstones and blackband ironstones in 

 the Carboniferous strata of England and Wales are estimated 

 by the Survey at 1,057 million tons. The Scotch Coalfields 

 are estimated to have a reserve of 93 milUon tons of ironstone, 

 making 1,150 million tons in all. Much is inchided that in all 

 probability will never be mined. The richer and thicker seams of 

 blackband have long since been worked out, and the present output 

 comes mainly from North Staffordshire and Scotland. In 1918 out 

 of a total output of 1,120,000 tons of Coal Measure ironstone, 

 1,052,000 tons came from those districts. The clay-ironstones, too, 

 are not worked systematically except in a few places ; in many 

 collieries the clay band ribs are only taken down in '"' brushing " the 

 roads, and in the case of a ball-ironstone the balls are put aside as 

 they occur during the working of the coal, or fireclay, as the case may 

 be, and marketed when a sufficient quantity has accumulated. The 

 output of Coal Measure ironstone, which amounted to over 6 million 

 tons per annum in the 'seventies, has been falling for many years, 

 and is now little over a milUon tons per annum. The Director of the 

 Survey, in an introduction to the Memoir on the Carboniferous 

 Bedded Ores, states his belief that under present conditions only 

 about half the amount estimated would be available, and in the 

 Memoir dealing with the iron-ores of Scotland a 30 per cent deduction 



