The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1901-07-07

1iie discovery OF TWO mountains OF
abrasive stone, which assays more than
one-half oxide Of alumina, the basic of
corundum, in Lake county is expected
to make not only a vast addition to the
mineral wealth of Minnesota and Amer
lea, but immense fortunes for the little
party of Duluth men who will control
the discovery.
The cleverly guarded secret of the dis
covery of two immense deposits Of abra-
sive stone on the north shore, Lake Su-
perior, have recently come to light after
the discoverer and his friends, working
under cover for two years, have succeed
ed In acquiring title to all Of the lands
involved. The find is said to be one of
the most important of American min
eral discoveries, and will result in turn
Ing into American channels an emery
stone and dust trade, now going to Eng
land and Turkey, estimated at $15,000,0J0
annually.
The immensely Of the deposits, If all
the claims Of the discoveries are borne
out, will at once make Minnesota one of
the most important factors in mineral
production and will seriously impair the
corundum of Canada and North Caro-
lima. The find embraces two mountains
Of what Is said to be the purest corun-
DUN in the world One of the noun
LdlIlSJ CdIlSlOH pSdhy IISGS JLt l6GL dDONC
the lake level. It has an area of 800
acres, under which lies the valuable
corundum rock to a depth Of more than
zoo feet. Twenty-Five miles farther up
the shore, at Baptism bay, Is Baptism
mountain, another mass Of the abrasive
rock, with an area of 800 acres.
On both the properties are fine water
powers, and both are Immediately ada
cent to the lake and the worlds cheap
oe,Ee Chi rfa
is claimed, be quarried, refined and
placed on the market for Sc per ton. AS
emery is sold in the American market
for from sos to $1O0 per ton, and the
North Carolina and Canadian corundums
find ready sale at $24O per ton, it is easy
to see the fortunes that the present
owners are likely to accumulate.
The discovery was made in May, 1899,
by E. e. Lewis, of Duluth, a practical
mineral explorer, who was cruising up
the shore region prospecting for iron.
The high abrasive quality of the stone
was accidentally called to his attention.
He wisely held his peace and secured
assays Of the rock. The assay exceeded
his widest expectations. The rock was
shown to be a composite of lime, silica
and oxide of alumina, the latter assay
ing 54.40 per cent, While the finest Ca
madam commercial corundum mines con-
Carolina mines run on an average only
per cent and In both instances the de-
posits are in narrow sac veins.
A half dozen Duluth men, among them
former United States Senator Charles
A. Towne. former State Factory In
spector Alfred McCallum, Axel Wick
strom and T. B. Lewis, a brother of the
discoverer were let into the secret.
They went quietly to work to buy up
the mountains, and recently succeeded
in realizing the hopes of a close cor
poration. Both Carleton peak and Bap-
tism mountain, together with Baptism
bay, are theirs. Docks will at once be
erected at Baptism bay and mining OPP
erations commenced this year.
Experimental tests were made in st.
Paul last Tuesday with wheels made
from the Minnesota stone, which proved
to the satisfaction OF the experts wit
Messing them that even in its crudest
state the Minnesota rock as an abrasive
is superior to the finest commercial CO.
rUndum now on the market. It is
cooler abrasive. A pocketknife blade
was ground to a razor edge on a stone
revolving $500 times per minute without
perceptible heating, or in the slightest
affecting the temper of the blade. 1t is
more enduring composite, and it is
claimed for it that the best results can
be obtained at a much lower rate of
speed than with either emery or corun-
dunn.
The tests made at the Greengard Plat
ing works, $50 East Sixth street, were
witnessed by Prof. Winchell, Of the state
university; Prof. Calvin, Iowa state
geologist Of Iowa City, and Prof. A. J.
Woolman, of the Duluth high school.
A wheel made of the Minnesota stone,
valued at 40 cents, was tested with the
| best grade emery wheels and a corun-
dunn wheel which retails at IS. The
Minnesota stone cut through the hardest
tool steel and files as if they were
cheese without burning the metal, smear
| Ing or peceptibly wearing the stone.
| The corundum wheel, put to identically
| the same test, showed nothing like the
| same abrasive qualities, burned the
metal and showed marked wear. All the
wheels were run at $500 revolutions per
| minute, the most advantageous speed
| for the emery and corundum, while it
was claimed the Minnesota stone would
produce much better results at 1,60O rev.
olutions per minute, which carries with
it the added value of power economy.
The stone used was, chemically, in its
mining state, and it Is claimed that by
vitrifcation the abrasive properties may
be increased from % to so per cent The
method Of preparing the stone for tho
market is simple and inexpensive The