1875. Metallurgy. 113 
7 
fissure was first formed, accompanied probably by a shifting of the strata, so 
that a number of open spaces were left, and into some of these cavities frag- 
ments of the walls would eventually fall. These fragments were cemented 
into a breccia by the subsequent deposition of the cab, a sort of hornstone, 
which more or less completely filled up the fissure. Ata later date the fissure 
was reopened, and lined with successive layers of quartz, galena, carbonate of 
iron, and calc-spar, together with fragments of the walls and of the prior- 
formed vein-stuff. 
As it is of first importance to encourage habits of accurate observation 
among the young men engaged in our mining industries, we gladly call atten- 
tion to a very creditable paper by Mr. A. K. Barnett, of Penzance, in which he 
offers some observations on the mineralogical and physical characters of the 
Elvan courses, the greenstones, and the sandstones of Cornwall, with remarks 
on their associated minerals. This paper, accompanied by a map of Cornwall, 
showing the Elvans and other intrusive rocks, is published.in the last ‘* Report 
of the Royal Cornwall Polytechnic Society.” It is well known that the Elvan 
courses are intimately connected with the copper and tin lodes, on which they 
are generally believed to exert a beneficial influence, bunches of ore being 
frequently found at their intersection with the veins. A large number of the 
Elvans were examined by Mr. Barnett, who obtained a sufficiently fine col- 
lection of specimens to receive the Polytechnic Society’s medal. 
Whilst cross-sections of individual mines are frequently made, one does nat 
often have an opportunity of seeing general transverse sections showing the 
connection of one mine with another, such as those recently prepared by 
Captain Maynard, of East Pool Mine, and described by him in the ‘“* Repdrt of 
the Cornwall Polytechnic Society.”” By studying these sections, some of which 
are carried over several miles, and comprise anumber of mines in their course, 
many facts are brought out which would probably be lost sight of in the study 
of sections which represent only individual mines. 
In a paper on the ‘*‘ Geology of North West Lincolnshire,” recently read 
before the Geological Society by the Rev. J. E. Cross, the position of the Lin- 
colnshire iron ore, which of late years has been largely worked near Froding- 
bam and Scunthorpe, was carefully examined, and its geological horizon defi- 
nitely determined by palzontological and stratigraphical evidence. It appears 
that this iron ore occurs in the lower part of the Lower Lias, in the zone of 
Ammonite semicostatus: It is therefore much lower in the geological series 
than the celebrated Cleveland ironstone, which occurs in the Marlstone or 
Middle Lias. Possibly,the ironstone worked at Caythorpe, near Grantham, 
may lie on the same geological horizon as the Frodingham ore. 
A series of papers on the iron industries of this country is in course of con- 
tribution to the ‘*‘ Mining Journal,’ by Mr. Richard Meade, Assistant Keeper 
of Mining Records. The series commences with an article on the ironstones 
of Northamptonshire, and the history of iron smelting in that country. From 
the writer’s position in the Mining Record Office, the statistical information in 
these articles will be in the highest degree trustworthy. 
METALLURGY. 
The present position of our metallurgical industries is well shown in the 
following general summary of the quantities and value of the several metals 
obtained from ores raised in Great Britain, during the year 1873, according to 
the statistics recently published by Mr. Robert Hunt :— 
Quantity. Value. 
LEVEN 960) oo) eabe NOE Tons 6,566,451 $18,057,739 
eI e lise, rac drsis | Says mp 9,972 1,329,766 
‘Copier. | ke Vio Yee soe ” 5,240 502,822 
Wade ap inst) cia) war as a 545235 1,263,375 
SIV Cigaameal ict se est hen OUNCES) IsQ47077 131,077 
Ei. Got tte Uo eon O6 Tons 4472 120,099 
Other metals (estimated) —_ 5,000 
Total value £21,409,878 
VOL. V. (N.S.) Pp 
