M A R C H 1 9 4 0 ^ ^ ^ V O L U M E 30 No. 3 - Mines Magazine

"A LIFETIME at
HARD LABOR".
This is f — P-i^als"'S;
£^rbesfSd"to?udre. «ve these
X wheels a work-out on your
own 'Voelc piles" and be sure of
Zwest cost per ton mrle haul.
CS.Ca
ISO'""; J "
Denver. Colorado.
• FLEXCO H D RIP
PLATES are used in repairing
rips and patching
conveyor belts. The
wide space between
outer baits gives the
fastener a long grip on
ttie edges of the rip,
while the center bolt
prevents the fasten era
from bulging.
Keep your conveyor
belts going with
FLEXCO I
BELT FASTENERS
• Avoid shutdowns and lengthen the
life of your conveyor belts and bucket
elevator bells by using Flexco HD belt
fasteners and lip plates. Thousands of
companies have stepped up the performance
of conveyor lines and cut costs
by using Flexco methods.
Bulletin F-lOO shows exactly
how to make tight'
• FLEXCO H D BELT
FASTENERS make a
strong, tight bull joint butt joints in conveyor
with long Hie. Recessed
plates embed Fasteners. Also illustrates
belts with Flexco HD Belt
in belt, compress bell step by step the latest
ends and prevent ply
separation. Five sizes
practice in repairing rips
if. sleel and alloys. and putting in patches.
FLEXIBLE STEEL LACING COMPANY
4628 Lexington St., Chicago
FLEXCO
-X]-_> BELT FASTENERS
Sold by supply houses everywhere
R A P A I Kl ^ FROM YOUR OFFICE SUPPLY
D A M V V J ^ A I I ^ ^ HEADQUARTERS
In Our Furniture Department
On Second Floor WORK
ORGANIZERS
(Values to $3.75)
for $1.00
POLAROID
LAMPS
(Reg. $12.75)
for $4.75
A GROUP OF
HOME DESKS
25% off
DENVER, COLO.
DESK LAMPS
(Various styles,
Values to $30)
for $2.50 to $10
EMERALITE
LAMP
(Reg. $30)
for $10.00
KISTLER
BUILDING
Mechanization—
(Continued from fage 118)
petroleum, a very large part oi this
coal may never be recovered.
The mercury mines oi the United
States are comparatively unimportant
at present due to the fact that the ore
is rapidly being exhausted. The New
Almaden mine in California was closed
in 1926 for want of ore, although
it had produced between 65 and 75
million dollars worth of mercury and
was the deepest mercury mine in the
world. The New Idria mine, also
in California is at present the greatest
producer in the United States, but
in spite of the application of mechanical
aids in mining, its costs per
unit are increasing.
In general, all of the mineral industries,
where the pinch of increasing
natural handicaps is not yet serious,
show particularly rapid increases
in productivity in the period frora
1919 to 1929 and probably even
greater increases since then. In copper,
iron ore, phosphate rock and
gypsum productivity doubled between
the World War and 1929. In bituminous
coal, the largest of the mineral
industries, the record is one of
steady increase.
Although the Lake Superior district
is the oldest copper camp in the
United States, it is still responsible for
more than 7% oi the U. S. supply.
The effect of mechanization in these
mines is clearly shown by the following
quotation from U. S. B. M. Bui.
306, p. 337, "Along with power drilling,
concentration of haulage, and selective
mining, scraper loading has
been one of the principal economies
that have enabled the Michigan copper
mines to combat the difficulties of
increasing depth and to survive the
competitive struggle."
The graph on page 12 shows how
the yield of copper per ton decreases
with increasing tonnage treated in
spite of improved methods of extraction.
It will be noticed that since
1910 the effect of business depressions
on this curve is to increase the yield
of copper per ton of ore and to decrease
the number of tons treated. In
other words, the number of tons of
ore treated each year depends upon
the price of copper, and the tonnage
curve roughly parallels the price curve,
while the yield per ton curve (or
grade of ore curve) is the reciprocal
of this. Graphs of the other base
metals would be similar to the copper
graph.
While all branches of industry have
tended to grow rapidly in tbe United
States, the mineral industries have developed
faster than any other major
division, far outstripping agriculture
and exceeding even the growth of
manufactures and rail transport. The
following table shows how the growth "
of mineral production from 1899 to
1929 compares with that of population,
agriculture, manufactures and
rail transport.
Percent inrrease
froin 1899
Item LO 1929
Population _._ —- 62%
Agriculture - 48%
Manufactures 210%
Transport, railroad ton miles-238%
Mining - 286%
The following table shows the increase
in horsepower used in all the
mining industries:
H.p. of
electric motors
IT.P. of prime driven by
Year movers purchased energy Total H.P.
1902 1,636,4-90 19,764 1,656,254
1909 3,179,270 205,489 3,384,759
1919 3,341,350 1,558,752 4,900,102
1929 2,502,132 4,467,959 6,970,091
^ Year
Horsepower
per worker
1902 2.78
1909 3.78
1919 4.45
1929 6.97
Mechanization in the mineral industries
has greatly improved the welfare
of miners in many ways. First,
it has relieved them of much drudgery.
In 1842 a British commission reported
that girls and boys under ten
years of age were working as draft
animals in the low drifts of coal
mines: "Chained, belted, harnessed
like dogs in a go-cart, black, saturated
with wet, and more than half
naked—crawling upon their hands and
knees, and dragging their heavy loads
behind them—they present an appearance
indescribably disgusting and unnatural."
Now mechanical scrapers,
power shovels, electric locomotives and
powerful hoists assume the backbreaking
labor of getting the ore out
of the ground.
Second, mechanization bas improved
the working conditions of the miner.
The great mines of the Comstock
Lode were proud of their mechanization;
men working at headings where
temperatures approached 120° F. and
the candles burned blue in the foul
air-—-"By the compressed-air pipes,
the five or six men at a heading receive
fully 700 cubic inches of air
per minute." With the application of
electric fans and blowers miners receive
hundreds of cubic feet of "conditioned"
air per minute.
The psychological effect of mechanization
on the welfare of the miner is
fM ' i i
more abstract, but is probably greater
than the physical effects obtained. It
is probable that the welfare of the
miner has, been improved more by
mechanization than that of any worker
in other industries.
The average annual wage of miners
in the United States has been as follows
:
Average annual
Year
v/sgc of miner
1902 - $ 580
1909 - 620
1919 -.. 1,465
1929 1,066
1935 (Au, Ag, Pb, Cu, and
Zn mines) .._ _ 1,070
It is probable that mechanization
has decreased and will continue to decrease
the amount of seasonal changes
in employment, particularly in the
coal mines. As the investment in
machinery increases in these mines, the
fixed charges also increase, until a
point is reached at which it is more
profitable to keep a mine in constant
production rather than in seasonal
production. Although it is evident
that the mechanization of the mineral
industries has decreased the actual
number of workers emploj'ed, I believe
that the economic status of those
remaining in the industry is improving
at a greater rate than would have
been possible under other conditions.
It is evident that mechanization of
the mines in the United States has
made mineral production more rapid,
and therefore, the state of exhaustion
is, proportionately, closer at hand. At
the same time, it has reduced the costs
by increasing tbe production per man,
thus making possible the exploitation
of mineral deposits which were formerly
too low grade to be worked
profitably. But, there must come a
time when the difficulties to be surii
inrirrM
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