The Daily spy. [volume] (Worcester [Mass.]) 1845-1850, 1849-09-08
THE COPPER REGION OF LAKE SUPE.
RlOQ

traveller, one by Dr. Jackson, and the other by
Dr. J. l.. Hodge, giving interesting descriptions
of the copper region OF Lake Superior DR.. Hodge
says that many OF the veins are not worth work.
ilg, and that OF others, tits not yet known wheth
er they will be worth working.
The names of the mines which have proved
profitable, are the North West, Cliff, North
American, and Minnesota. Other mines similar.
ly situated, and representing equally favorable
external features, and which have already fur
nished some copper, the North Western,
Albion, Douglass, Houghton, Algonquin, and
Ontonagon cot Boston) These are at present ly
ing idle only for want of the necessary capital to
work them.
1.-THE cliff Mine, owned by the Boston and
Pittsburg Company OF which David Henshaw, is
President, is by far the most valuable, and is
earning more than 100 per cent year OH the
capital stock
The lodes consist Of veinstones, as quartz, lau-
monte, Gale, spar, prehnite, epidote, and chic
rite, with fragments Of the wall. rocks. Native
copper in fine particles, Jumps, and sheets, are
intel spersed through these gangues, and huge
masses OF the metal lie longitudinally along the
course of the iodes. Their shape is that OF clip
soidal sheets; and they stand on their edges,
sometimes several arranged side by side. Ma
tive copper also penetrates the wal-rocks; form.
ing "stOc Oerks" which have sometimes led to
extensive explorations entirely off the veins
one side or the other the vein cleaves perfect
ly from the wall; on one side il often clings to
it.
The mines are wrought wholly for native cop
per. The yeinstone with scattered particles fur
nish what is called stamp work, which is crush.
ed under heavy stamps and then washed; the
Jumps are called barrel ore, being packed in bar
rels Tor transportation; and the masses after be-
ing cut up into pieces not exceeding two tons in
ares in hill q,
OF these masses is so enormous as almost TO ex
coed belief. They have been broken up in the
Chf mine OF 90 and even go tons in weight
such pieces are reduced in the mine to fragments
OF seven tons weight and less, and after being
hosted to the surface are still farther reduc-
| ed
AT the Minnesota Mine; near the Ontonagon
River, had an opportunity OF examining in June
the most extraordinary mass yet met with. Two
shafts had been sunk on the line OF the vein $50
feet apart. At the depth of about 80 feet they
struck massive copper, which lay in huge
sheet with the same underlay as that OF the vein
about 55 deg. towards the North. Leaving
this sheet as hanging wall, level was run un.
der 1t connecting the two shafts For this whole
distance OF $50 ieet the mass appears to be con.
nuous, and how much farther it goeson the line
OF the vein either way there is no evidence, nor
beside to what depth it penetrates in the solid
vein. l examined it with care, striking it re-
peatedly with my hammer in order to detect il
pRipsfibis by the sound any break or interruption
stone encrusted it sometimes and concealed the
lace oil the metal. Examinations had been mado
by drilling through this scale, where it attained
/ ,he 'nicKness OF an inch or so but in no place
had any sign of break been found. II formed
the whole hanging wall Oil the level. sbosins
width OF at least eight feet above the floor in
-Whlch It's lower edge was lost 1t had been cut
'nrougn In only one place, where partial break
aHorded convenient oppoIt unity Measuring
the thickness here as well as the irregular shane
oil the gap admitted, it was found some what to
exceed five feet. Assuming the thickness 10 av.
erage only one foot, there would be in this mass
lzoO cubic ieet, or about $50 tons-st:l if is mt
sale 10 assume even one foot, for the masses vary
extremely in thickness
Inc mode adopted to remove these masses il
to cut channels through them with cold cbiseIs
alter they are shattered by large sand blasts put
IN behind them. Grooves are cut with the chs
els across their smallest places, one man holding
ana another striking, as in drilling. A chin Of
copper oil an inch wide and up to six inches
IN iehgih is taken out, and the process is epeat
ca unlli the groove passes through the mass
l ne expense OF this work is from IS TO SI2 ner
SuPerncial loot of the face exposed Fragments
oi Nelhstone enclosed in the copper prevent the
-, A PoWeriul machine, 0ccupyinp |
niue room, is much needed, which would ner.
form more economically this work
Inc greatest thickness of any mass cut.tbrouob |
at the Cllfl Mine has been about three iaet
ihelr occurrence through the vein is not reg,.
lar. Barren spots alternate with productive por.
ions. The same is the case in all the mines
ne total product Of the Cliff mine for the wear
1915 is estimated at $50 tons, averaging 60 ner
cent During the present year, more than baIf
this amount has been already sent down and
mere is enough more on the surface and in s;gbt
III tne NINE to warrant the belief that 1000 tons
VIII be the product OF the years work. or 6oo
IONS OIL copper. The whole amount of conner %
huaiiy imported into the United States is ahon,
tne value OF 900, or about $500 tons. Rnt
,itle mas been supplied from our own mines
Nine SUCH mines then as the Cliff would render
US Ina dependent OF foreign supplies From pres
eht appearances, after careful examination ~ ,ha
region, and consideration OF the progress made IN
mining since my last visit in 1876. / feel nysairl
warranted In expressing decided conviction ,b,t
. .his amount OF copper must be supplied in very
lew years, and this metal soon become. M ,eaJ
already has, one of EXPORT instead ofimport IT,
recent failures Of mining speculations widely nm.
dertaken, and ignorantly and extravaeantIy CON.
ducted, may Tor time check the develonment oe
these mines; but their wonderfully rich cba,ac
Ter is now beginning TO be properly appreciated
as well as the reliance, which NAV be put in tbe
surface. appearance Of the VEINS 49,
The silver found associated with the conner hoe
not proved OF much imnnrfanca |