58 



he finds that mercury thoroughly boiled in clean glass tubes 

 does not show a convex surface, but adheres strongly to the 

 glass. However he has confidence in giving the following 

 results in working with his apparatus, with acid of various 

 streng'th, obtained by successive dilutions of sulphuric acid, 

 of sp. gr. 1.845 by volume. 



Pressure in Inches 

 Water. of Mercury. 



Inappreciable. 



1 Inappreciable. 



2 O'Ol at 70° 



1 0-03 at 63° 



2 0-15 at 63° 



4 0-30 at 55° 



1 0-37 at 47° 



"Notes on supposed Glacial Action in the Deposition of 

 Hematite Iron. Ores in the Furness District," by William 

 Brockbank, F.G.S. 



The hematite iron ore deposits in the Furness district 

 are of two very distinct varieties — (1) Those filling hollows 

 in the limestone, covered only by the post tertiary gravels 

 and clays, and (2) Those occurring in the carboniferous 

 limestone in veins, and large irregular cavities, or " pockets." 



The summit of the mining district of Dalton-in-Furness 

 is High Haume, which rises about 508 feet above the level 

 of the sea, and is of Silurian age ; Coniston limestone, grits 

 and flags ; upon whose flanks rests the carboniferous lime- 

 stone. The uplifting of this central cone tilted the lime- 

 stones, so that they dip very quickly towards the S.E., and 

 broke them up into a succession of reefs, the outcrops form- 

 ing a parallel series of ridges from W. to E., each marked 

 out on the surface by lines of iron ore workings. 



The source of the hematite ore appears to have been, here 

 as elsewhere, at or about the junction of the silurian slates 

 with the carboniferous limestone; and it found its way into 



