51 
supply, having obtained some years since a beautiful speci- 
men in all respects exactly similar to Dr. Brown’s, from the 
Roof mine lying immediately over the Gannister seam in 
the lower part of the Lancashire coal field ; so there is no 
doubt whatever that the fossil cone is of carboniferous age. 
Mr. E. Bcwman, M.A., exhibited Helmholtzs Double 
Siren, and explained its action and peculiarities. 
“ The Hematite Iron Ore Deposits of Whitehaven: Notes 
on the Aldby Limestone, Gleator Moor,” by W. Brockbank, 
F.G.S. 
The mountain limestone of the Cleator district forms an 
escarpment to the valley of the river Ehen, from Egremont 
round the base of Dent Fell, towards Cockermouth. It rests 
upon the old clay slate of Skiddaw and Dent, and is the 
outcrop of the Whitehaven coal field. It contains most ex- 
tensive and valuable deposits of hematite iron ore, and is 
therefore an interesting subject for study in any aspect which 
will throw light upon the question of the origin and deposi- 
tion of that valuable mineral. The general character of the 
hematite deposits in this limestone was briefly sketched by 
the writer in his remarks to this Society, Dec. 10th, 1867, 
and which were printed in the Proceedings — p. 59-61. The 
object of the present communication is briefly to describe 
the section of mountain limestone exposed in the quarries 
of the Whitehaven Hematite Iron Co., at Aldby, on Cleator 
moor, and its surface as affected by diluvial and glacial ac- 
tion — believing that both these points have a considerable 
bearing upon the subject of the occurrence of hematite iron 
ores. 
