The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1921-11-25

prepared by the United States Department
of Agriculture.)
Distribution by the United States
Department of Agriculture Of 12,5OO,-
600 pounds of picric acid salvaged
from the war stores and designed to
be used for farm explosives Will
arouse interest in the desirability and
practicability of blasting stumps to
clear off old wood lots for crop pur-
poses.
The picric acid for distribution has
been allotted to the states according
to areas of cut-over lands. 1t Is
planned to establish an agency in each
state to cooperate with the depart
ment, and the agricultural college in
each state has been asked to act in
that capacity.
Not Commercially Available.
Picric acid is rather higher In ex-
plosive power than ordinary CONNER
cial dynamite as used in agriculture,
but for manufacturing reasons is not
likely TO be on the market after the
governments supply is disposed OF.
For stump and rock blasting work it
is used in practically the same way,
being exploded by q decorating cap,
either with fuse or an electric det-
onator.
In blasting stumps, the proper loca-
ton and size Of the charge depend
upon the kind, size and age of the
stump; the kind Of soil and the
amount of moisture in It and the
method of firing the charge which is
to be used.
For tap-rooted stunps good meth
cd is TO dig away enough earth at the
side to permit boring an inclined hole
wei down past the center ar the
depth where it is desired to cut the
root of. The hole should be at least
eight inches deeper than the length OF
the cartridge to allow for tamping.
This charge may be fired by fuse or
electricity, or two or more charges
may be placed in holes around the
outside of the root and fred with an
electric blasting machine. Sometimes
even one large charge, planted deep
on the outside of the root, will do the
work.
Where stumps have lateral roots
some experience and judgment will be
necessary in placing the explosive, es-
peciany If only one charge is used
Generally the center of resistance will
be the center of the stump, although
sometimes roots on one side are much
stronger than on the other.
The depth requires careful consid-
Grafton. For small stumps the charge
should be at least two feet deep, while
larger stumps with wide-spreading
roots should be loaded deeper. Sandy
soil requires deeper charge than clay
or loan.
Size of Charge.
The size of the charge cannot be
specified briefly, but one authority
recommends roughly one-half pound
of 20 per cent dynamite for each
square foot of stump. With picrie
acid, cooperative investigations by the
United States Department of Agricul-
ture and other institutions indicate
that success can be attained with one.
fourth of a pound for each square foot
of white-pine stumps, with larger
charges for hardwood stumps. The
inexperienced blaster should begin ex.
periments with small stumps and ad.
just the charge.
Holes in soil may usually be made
by driving q 11s-inch crowbar with q
ten-pound maui. In wood, of course
an anger is required. Sometimes it is
wise to set off small charge in the
bottom of the hole to form a chamber
and after the hole has cooled lamp II
dry, the paper covering Of the car
trfdges may be slit with a sharp knife
and the cartridges tamped into a solid
mass with wooden stick Cartridges
may be divided by Sitting the paper
around and breaking. Never attempt
TO slit a frozen cartridge.
To prime the charge, cut off the
proper length Of fuse, allowing at least
2 feet per minute required to get to
safety after firing.
Open the cap box and allow one can
TO slide into the hand. Never pick or
pry out cap with a stick or wire, as
they are very sensitive. Slip the end
OF the fuse snugly into the open end
Of the cap. Crimp the cap on with a
crimper. If the charge is TO be fred
in water, apply little grease around
the top of the cap.
With the crimper handle, or a stick
the size of lead pencil, make a hole
in the side of the cartridge, inclining
it so the part TO be occupied by the
cap viii be parallel with the side OF
the cartridge. If the cartridge Is to be
fired under water, apply some water.
proofng substance. Tie the fuse in
place with string around the fuse
and the cartridge Then carefully
place the cartridge In the blast hole,
making sure the cap stays in position.
Printing for electric discharge is much
simpler. Directions go with the ap-
paratus.
Wooden Stick for Tampina.
Having placed the primed charge. it
is necessary TO lamp 1t. Any straight
round stick. about IL inches in d.
aIneter and feet long. win do for