The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1874-07-25

.. ,,sss L, ars and all
~ srn onS In the a0 NJ NJ
Az a9ieos,aie ground connect hon. . a ~
. = ~ inslsatton by way of eress.ls
r pa .r against the passage o. &C
s,i..ses conpsete misapp o as,.., ~
~. S,netIon III the rod and OF the quarry os
/; ssaIattnn. Ipgulators are oniS capsv, 60.
arrestsng fke movement OF caIreu.s " o.,,a an
fei ELECTRICITY. They answer 20 $50, n
tho wires the currents Of low tension use 49,
ie,acr.rjsv. but do not preyehas. Ine l,en
rom betng shattered II the wire = sslusA -
lightnirg. :, ,,,ar .,e tr,a nath
nc lest resistance was clearly lliustratea 10
The ease OF building on Staten asland STRUCK
sos.,e years ago by q discharge OF lightning,
which. although received upon Lightning.
rod at one end, left the rod and went through
the wall TO looking.glass IN the SECOND
story. The discharge blackened tne'qmck-
silver on the back Of the glass, ana from
thence leaped to the body OF q man VINO was
standing In frcnt OF it, Down his I,nos anu
through the floor to the corner OF stove.
pipe immediately underaeath, upon which
it travelled across and down 10 o stove az Tue
opposite end Of the lower story, Wnere
it again went through the moor ana SO
Uu,
that if there had been q rod leading to
the ground at both ends Of this building, and
n rod across the roof connecting them to.
pether. the fluid would have been provided
via line OF conducting matter which, by
reason of its continuity, would have pre-
sented less resistance than the substances
which interviewed between the detached con-
Meeting materials upon wtsch the discharge
actnalIy passed. A somewhat similar Incl
dent occurred many years,ago in Poughkeep-
sic. where a discharge of lightning passed
across building upon bell-wire and Killed
q man who was sitting Bpon the piazza with
his head leaning against the bell knob.
The position of danger in an unprotected
building is when the body is interposed be.
| tween TWO masses or lines Of metal; but II
iiphtnipc-rotls are applied by person com.
petent TO determine and provide for what
ever may be the peculiar exigencies OF the
case. then the rods will present the easiest
| path for the fluid ia any direction, and they
may be relied on as a protection, because
electricity in its passage from place to place
invariably selects the shortest path upon the
| best conductors
II is the junction Of the lghtning-rod to
facilitate the distribution OF electricity, ard
especially to promote the freest circulation OIL
rarified currents so as TO neutralZe an cleo
trical disturbance induced in the building
by thunder.cIoud. Insulation, while bay
| ing no effect as barrier against a discharge
of lightning, does prevent the rod from gra
dlaIly collecting electricity from the
building and silently giving it of to the
atmosphere. If insulated the rod can
not act as safety valve, and the
electrical equilibrium of the matter com
posing the building, if disturbed, can only
be restored by discharge to or from th'
rod. The experience of the last forty year,
has clearly established two things: first, tina
failures OF lightning-rods to protect hav'
resulted from defects which were obvious t
competent judges, and which could hav'
been easily avoided; and secondly, that Their
have been no such failures in the case O
rods erected in accordance with the pre-
scribed scientific conditions. Q.
New York, July 81, 1874.