The aegis & intelligencer. [volume] (Bel Air, Md.) 1864-1923, 1865-06-30
Aaritnltnral
About Lightning Rods.

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There are numerous kinds of patent
lightning conductors, each claimed by the
inventor to be superior to all others. We
cannot decide on the merits of the rival in.
ventions, butcan do our readers much better
service by pointing out the essentials of a
good Lightning rod. The following was
prepared some years ago by Prof. Henry,
the distinguished physicist, who has given
especial study to electricity, and it appears
to be perfectly plain and to cover the
whole ground. s,
"1st. The rod should consist of round
iron, of not less than three fourths of an
inch in diameter. A larger size is prefera-
BILE to smaller one.
"2d. 1t should be, through its whole
length, in perfect metallic continuity; as
many pieces should be joined together by
Welding, as practicable, and when other
jennings are unavoidable. they should be
made by screwing the parts firmly togeth-
er by coupling ferule, care being taken
TO make the upper connection Of the latter
with the rod water-tght, by cement, SOL
der, or paint.
"3d. To secure it from rust, the rod
should be covered with coating of black
paint. ..........,
'4th. 1t should be terminated above,
with single point, the cone of which
should not be too acute, and to preserve
it from the weather as we'll as to prevent
melting, it should be encased with plati-
nun, formed by soldering plate of this
metal, less than twentieth of an
inch in thickness, into the form Of hol-
low cone.
18th. The shorter and more direct the
rod is in its course to the earth, the bet
ter. Acute angles made by bending the
rod and projecting points from it along its
course should be avoided.
seth. 1t should be fastened to the house
by iron eyes, and may be insulated by CYL
inders of glass. We do not think the lat
ter, however, of much importance, since
they soon become wet by water, and in
case Of a heavy discharge are burst asun-
der. sd.
"7th. The rod should be connected with
the earth in the most perfect manner pos
sible, and in cities nothing is better for this
purpose than to unite it in good metallic
contact with the gas mains or large water
pipes in the streets; and such a connec-
ton is absolutely necessary if the gas or
water pipes are in use within the house.
This connection can be made by solder
ing to the end of the rod strip Of copper,
which after being wrapped several times
around the pipe, is permanently attached to
it. Where connection with the ground
cannot be formed in this way, the rod
should terminate, if possible, in a well, al
ways containing water, and where this ar
rangement is not practicable, it should ter
inmate in plate of iron or some other
metal buried in the moist ground. 1t
should, before it descends to the earth, be
bent so as to pass off nearly perpendicular
to the side of the house, and be buried in a
trench surrounded with powdered char
coal. .t..
"Sth. The rod should be placed, in pre-
ference, on the west side of the house, in
this latitude, and especially OH the Chin
= ney from which current of heated air as
cends during the summer season.
18th. In case of a small house, a single
rod may suffice provided its points be suf-
iiciently high above the roof, the rule be-
ing observed, that its elevation should be
at least half of the distance to which its
protection is expected to extend. It is
safe, however, particularly in modern hou-
ses in which a large amount of iron enters
into the construction, to make the distance
between two rods less than this rule would
indicate, rather than more. Indeed we see
no objection to an indefinite multiplication
Of rods to house, provided they are all
properly connected with the ground and
with each other. A building entirely in
closed, as it were, in a case of iron so con-
nected with the earth, would be safe from
the direct action of the lightning"