192 Burton: The Cleveland Ironstone. 
were worked years ago, and the mines were again recently 
re-opened, and although now closed it is quite possible that with 
a lower carriage rate to the furnaces they may again be worked 
in the future, especially if the stone can be calcined where won. 
In Rosedale, the Dogger proper, that is the bed lying on the 
top of the Alum Shale, reaches a peculiar development, and 
in places on the east side is, or rather was, as much as 14 feet 
in thickness of good ironstone, but although a good thickness 
is maintained the quality deteriorates so much that, in the 
words of the lessees, ‘it is really no use.’ On the west side 
the seam varies from about eight feet thick at the outcrop to 
five feet where work was abandoned in Sheriff's pit owing to 
water. : 
The. useable stone gradually got narrower as the work 
extended, and the working place was only about 80 yards wide 
when left. The stone on the west side gradually ‘ nips out.” 
The Carlton Iron Company, Ltd., kindly gave me the above 
particulars, and their man, who latterly had charge of the 
Rosedale mine, adds, ‘ On the west side there is a gradual nip 
out all along the workings. We worked many places as low 
as 18 inches. The indications were that the ironstone was 
entirely disappearing and that the shale (a clayey material) 
and belmonite (a hard flinty material, not sandstone) would 
eventually join. There have been no proved indications in 
the Farndale Valley adjoining that a workable stone exists, 
although traces are found of an inferior stone at a lower level.’ 
Below the dogger, and in a hollow in the alum shale, the 
magnetic ore was found forming a lenticular mass about 70 
feet thick in the thickest part. 
Rosedale may be said to be practically worked out, and 
probably 8,000,000 or 9,000,000 tons have been obtained from 
that source. 
The quantity of stone available has been very variously 
estimated by different writers. Joseph Bewick, writing in 
1860, estimated the available quantity of workable ironstone 
at 4,820,659,200 tons, sufficient for 680 years at 7,000,000 
tons per annum. He no doubt based his calculation on the 
Grosmont beds having a workable thickness over the whole 
of the Cleveland area. Mr. John Bell and Mr. John Jones 
jointly reporting to the Iron and Steel Institute in 1871, on the 
iron ores of Northumberland and Durham and the North Riding 
of Yorkshire, estimated the workable stone of the Cleveland 
main seam at 525,000,000 tons, basing their calculation on an 
area of about 27 square miles or say 17,500 acres, containing 
30,000 tons per acre. They erroneously report that the seam 
worked at Grosmont is the main seam. 
Mr. George Barrow, of the Geological Survey, in a paper 
read before the Cleveland Institute of Engineers in 1879, 
Naturalist, 
