Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1877-12-05
Clearing Land Of StumpS and BCulder'
with High Explosives.

Clearing Land Of StumpS and BoulderS
with High Explosives.
The attention of farmers having beer
recently called to this new method OF land
clearing, we have made it matter OF in
ouirv and are able to give the following
information, obtained from an expert in
their use, upon which our readers can
rely;
/. The high explosives most in use, in
this country, are rendrock, dynamite or
giant powder and dualin and are all gen.
orally termed giant po,Odcr. Of these
rendrock is the most extensively employed
in this section. Of that we shall particu-
larly speak, and what we say of it will ap-
ply in the main to the others.
>. Cosr OF WORKING. No. ? Rendrock'
which is efficiently strong is retaiIed at
irtv cents per pound. Fuse costs fifty
cents for one hundred feet and caps, one
of which is required for each explosion,
cost two cents each. A charge of half
pound well tempered will ordinarily dis
pose of stump ten TO eighteen inches in
diameter. Boulders are often broken by
exploding charge on them, which should
be placed at the point that would naturally
be selected for u JlotC Cih u Sledge ham,
,,ley. In most cases it is found to be more
economical to make use of IN inch drill
hole. A boulder of three tons would re-
auire an inch drill hole, say three to four
inches deep and a charge of rendrock cost
ing about twelve cents A boulder of ten
tons should have an inch drill hole from
ten to twenty inches deep, as the shape and
grain of the rock may demand. A charge
of rendrock costing about twenty cents
wonld break it in pieces. 1t will be MOTTO
ed that the cost of drilling is very small
compared with that required by blasting
with common black powder.
FIRING. Rendrock which is Of about
the same consistency as brown sugar, is
furnished in paper cartridges which cali be
safely cut to any required length. A fuse
of ordinary length for blasting is inserted
into heavy percussion cap, made for the
purpose, and the rim of the cap is pressed
down upon the fuse to hold it. The paper
on one end of the cartridge being pulled
up II hole is made in the rendrock with Il
sharp stick, Shout the size of Il lead pencil
and the cap with the fuse is punched into
it. When the charge is placed in its posi-
ton for discharging, the fuse is fired as ii
any ordinary blast.
In blowing stumps the better method i,
to make hole with an iron bar as nearly
under the center of the stump as possible
The charge is placed hard up against the
wood and made solid by filling under i
with sand or stones. Stumps can also bC
blown by putting an augcr hole in then
and loading as in rock.
In boring holes in boulders the rendrocl
is taken from the cartridge and packeC
into the hole with wooden rod This Cal
be done with perfect safety The cap will
the fuse is then inserted in this charge n
above described in the cartridge. Loading
boulders on the face is accomplished by
placing as many cartridges together a
are necessary, only one being loaded will
cap and fuse This charge is covered will
sand and, if convenient, stone that can b.
easily lifted put on top of that,
3. SAFETY. Rendrock is perfectly saG
to handle and transport with the SAM
care rs gunpowder. We may say safer
fire burns it without exploding unless
heat of about 5000 is reached. 1t freeze
ut 45"'and when in that condition, eXcep
in one way, is very difficult to explode, re
curing much heavier cap for this pur
pose, and an explosion of frozen rendrocl
when accomplished is so imperfect that
large part of its force is lost. The on
exception is this 1t is found that whel
frozen the cartridges become very hard an,
if forced into drill holes that are small 70
them an explosion will sometimes tax
place. This is probably the result of har
ramming producing high degree of heat
To avoid fatalities which might occur fror
such premature explosion, rs we'll us t
get the full power of the explosive whe
put to its legitimate employment, it
never used when frozen. 1t is easil
thawed by placing it in IL warm room
Boxes made with chamber for hot waite
on the principle ola glue pot are furnishe
for outdoor use, Some bury the cartridge
in heated sand. Either of these method
will keep the rendrock in fit condition t
work with perfect safety in the colde.
weather.
Our readers will find in our advertiser
columns the advertisement of Mr. Geo. II
Sampson, 25 Congress St., Boston, who i
the New England agent for rendrock an
comm on powder.