Saint Mary's beacon. [volume] (Leonard Town, Md.) 1867-1983, 1916-06-22
LIGHTNING A MENACE
ON THE FARM
Precautions To Be Observed In Pro
tectina Life And Property
From Lightning.
MYRoN sCREEsE,
Maryland State College of Agriculture.
City PRICES


Maryland State College of Agriculture.
There are a number OF types OF light
ming, the most common forms being
the "forked stroke" band lightning,
heat lightning and sheet lightning.
The last two forms of lightning are so
remote from the place where they are
observed that they ara perfectly harm
less Both the forked and band light
ming are extremely dangerous forms.
The dangers from lightning may be
classified as: ~ Dangers to person;
t2l Dangers to property In almost
every case the danger to person is linn
tied to shock which may result In in
jury or death. Danger to property in
eludes the injury or death to livestock
as result of shock, or destruction Of
buildings, trees. etc, either shattered
or set on fire.
Wise Precautions.
Statistics show that many persons
have been injured by lightning in open
fields, especially on hills towards
which the storm was approaching.
The only safe thing to do under such
conditions Is TO find a dry depression
in the ground and to lie down until
the storm has passed. II Is dangerous
to take shelter In a thunderstorm UNI
scr tree or small group OF trees;
lightning striking the trees may hes
diverted from the tree trunk through
the persons body to the ground or
falling limbs may injure him. If there
Il a tree or small group OF trees In an
open field, II "a safer to take up q
position near the trees but not under
them, because lightning is more liable
to strike tall trees. which act like
lightning rods, than thu person. A
person should take refuge in a build
ing before the storm commences and
avoid crossing an open field while the
storm II passing.
1t Is very dangerous to take shelter,
during storm, under a metal roof
which Il not thoroughly connected 10
the ground BY wires or pipes. Any
building. such as a dwelling house or
barn, Is not entirely safe shelter UNI
less II contains some well grounded
metal extending above the roof. In
unprotected buildings the most dan
serous places to occupy during a
storm are near chlmneys, freplaces,
and the walls.
Protection To Buildings.
Protection from lightning does not
consist In preventing the building
from being struck; but In providing
an easy path Tor the discharge to lha
ground. Lightning rods may be made
OF Iron or copper: but. on account Of
the rapid corrosion OF iron exposed to
the weather. It Is probably cheaper in
the end to use copper Rods should
be placed from 8 TO IL feet apart
along the ridge OF the roof and one rod
should be placed near each chimney.
Rods near chimneys should project
two or three feet above them aud
other rods should project at least three
feet above the ridge All rods should
DO fastened TO the roof with short
heavy screws, or bolts. Probably the
best form Of metallic connection be
tween the rods and the ground Is a
| loosely woven wire cable of small cop.
per wires. The crosssection Of the
wires In the cable should be about
equal 10 that OF solid wire three
eighths OF an inch In diameter The
copper cable should be In one con-
tinuous piece, from one ground con.
neetion near a corner OF the building
to the roof and down the diagonally
opposite corner to another ground con.
nection. The cable should be carried
| from the first ground up the side OF
| the building near corner, along the
cornice TO the ridge, along the ridge.
down the opposite cornice and down
the corner 20 the second ground. The
cable should be fastened to the rods
on the roof with special metallic
clamps: and to the building with spe.
cial forms of olamping devices or
ordinary pipe straps, the clamps OF
straps being secured with short, heavy
nails or screws. No sharp bends
should be made In the cable and Il
should be protected from mechanical
injury by mailing a strip of board OF
| moIding over the cable from the
| ground line to a height of about six
feet Ali spouting and any pipes, such
as ventilators, projecting above the
roof should be connected metallicaliy
TO the cable DO not use insulators
anywhere In connection with lightning
rods. With an L-shaped building. Il
is wise to connect third ground Il
the system at the angle Of the L.
j Proper Grounding.
BY grounding is meant the best cleo
trically conducting ground connection
to be found near the building which ii
to be protected Probably the 5esl
ground is a continuous extensive
metallic pipe system buried in tbs
Z earth, such as waterpipe system
4 The simple process of connecting tn,
cable to pipe driven several feet int,
j the ground IS not generally sufficlen
grounding. II an extensive water-pip,
system Is not available for grounding
J pit Two TO three feet In diamete
: should be dug down to permanen
. moist earth. The ground cone q
plate. to which the cable is secured
should be buried in the pit and sur
rounded with coke or charcoal to
depth of from one to two feet The pi
should then be filled in with earth Il
/ the ground level Soil saturated witt
] atahla drAinage makes an axcallan