Daily Kennebec journal., 1882-06-27
4aiIp 4tnnebtt yonrnal.
Protection from Lightning.

Protection from Lightning.
At this season of the year the subject of
protection from lightning is much thought
Of. To some persons every black cloud
that heaves up in the west upon sultry
days brings feeling of dread. 1t is not
strange therefore that they seek to know
and employ the means which may render
them secure fram the lightning's fash.
Lightning rods have been in use many
years, yet there is good deal of doubt
among common people about their
utility.
Recently, in England, there was held a
Lightning Rod Conference, the delegates
to which were among the most learned
and scientific men of the realm specially
qualified to deal with the subject for which
they assembled. These gentlemen came
together, and after comparing and dis
cussing theories and facts with thorough
ness. formed a code Of recommendations
in regard to protection against light
ming, which probably contains what is
known at the present time upon the subject.
Touching the upper terminal point OF
the rod, the report advises that. instead OF
being carried TO fine point, as is usual +,
it should preserve its full size nearly to
the extremity. and be merely beveled off.
For the purpose, however. of utilizing the
power of sharp points TO draw off silent
discharges Of electricity. it is suggested
that at distance of one foot below the
extreme top there be firmly attached. by
screws and solder, copper ring. bearing
three or four copper needles. each six
inches long and tapering from diameter
of quarter Of an inch to as fine point
as can be made. each to be platinized.
gilded or nickle plated. All vanes, finals
or other ornamental iron work on the up
per portion of building should be metal
ically connected with the conductor. As
to the material for rods, copper is pre-
ierred 10 iron, not because it is better
conductor. as is usually thought, but
chiefly because it is less likely to be
made useless by rust. Bad joints
must be carefully avoided, as they tend to
make the conductor source of danger
rather than measure of protection. OF
course perfect insulation must be pro-
vIded, and good earth connection must
in all cases be secured. Iron water and
gas mains answer an excellent purpose.
but connections should never be made
with lead pipes. on account of danger OF
melting. Where iron pipes are not used
the lower end of the rod should be sold
cred to plate of the same metal as itself,
having an area of not less than a square
yard. and the hole in which this plate is
sunk must be so deep that the earth sur
rounding the plate shall be moist even in
the driest weather. AS to the height of
the rod. the conference recommended that
it should be carried to such elevation that
a cone having its vertex at the upper
terminal, and its sides sloping at forty
five degrees. would enclose the whole
building. or as much of 1T as this particu-
lar rod is required to protect.
II these recommendations were strictly
followed. they would probably prove eff
fective and render houses and their occu-
pants as safe as any means yet discovered
by human ingenuity. Rods properly con-
structed and placed on buildings are a
safeguard, and it is by no means difficult
to have them so made and placed. But
unless care is taken. and the man who
erects the rod is watched. there is liable
to be some imperfection which makes the
outlay useless and sometimes worse than
useless.