Morning herald. [volume] (New York [N.Y.]) 1837-1840, 1840-06-02
Lightning Conductors Tor sh,p,.

The loss Of the ship Poland by fire, arising from
lightning, and the attendant circumstances lead Us
TO regret that the suggestions of men Of science re-
| spectiDg the employment of cenduc .ors, are no,
more attended to. In regard to tbeir efficacy the
seems To be no doubt in the minds Of skilful eectr
cIsns. Weare induced to repub ish an ESSAY which
| appeared IN Silliman's Journal some years ago
| since that period, similar views have been urged
| upon the British Government (and have been acted
| upon) by WIN. Snow Harris, Of the most dstin-
guished electricians of Europe The article is from
the pen OF DIR. Hare, whose know ledge and iudg.
ment on the question are of the first order-Nat
Gazette.
On the causes of the inadequate protection q Tordea
oy lightning Rods, IN some cases, and The means
OF msm1ns their perfect competency /; also a refs.-
tahon OF the prevalent idea that Metals are ye.
cuHarty aftractire Of Electricity; 6y X. Hare,
M. u Professor of Chemistry in tina University
of Pennsylvania.
In some Of our American newspapers. letter was
repubished from the Lon, on Times, calculated. a.
conceive, most perniciously TO lessen the conf
dence oi the public IN metallic conductors as means
OF protection against Lightning. In common with
many other persons the authOr Of the letter ars
TO suppose, that metals peculiarly attractive of
electricity; and iners that, when metallic rod Is
attached to house or ship, discharge OF electric
huiu may oe inauced from cloud, which otherwise
would not have been sufficiently near to endauger
the premises. Nothing, in my opinion, can be more
erroneous than this notion The truth is that the
earth and the thunder clouds being in opposite cleo
trcai states the electric fluid tends to prss from one
to the other, in order 10 restore the equilibrium
The atmosphere being nor. Conductor, through
whicha discharge cannot be accomplished without
foreibe displacement Of air, any solid body rising
above the earths surface which NAV be more ca pa
BILE than the air Of trans uniting electricity is made
the medium Of communication. Metals being pre-
eminenty capable Of acting conduc ors the trans
mission oil electricity Is made through them with
prepertionably greater facility Yet they do not at
tract II more than other substances similarly electric
fled. glass wooden ball, is as readily attracted
by the excited conductor OF an electr cal machine
10 ho nj moi nj md t~ls,
point, as the superfices of the ball may be greater
than that Of the point.
Nothing, to me, appears more u founded than en-
idea, lately suggested, that the attraction between
ship and thunder cloud can be increa sed, by the
presence OF pointed metallic rod surrounding the
main mast.
Ii houses or vessels have been struck with light
ming, while provided with conductors, it is i'm NV
opinion, ewing to the conductors being mproperlycon
structed; or having no adequate ctIeE with the
earth. Tho power Of any body to ceive an electric
discharge is dependant on the conducting power of
the meoium IN (which 1t terminates, no less than up
on Its own. A metallic rod, held by glass handle
or entering mass oil pounded glass, or dry sand
wosid not be more effcacious, a a conductor, than
q glass rod similarly situated. IL terminated by an
imperfect conductor, rs for instance, by earth or
water, ITS power is reduced in proportion to the i'm.
Perfection Of the medium thus bounding it. This
influence OF the media, in which conductors termi-
nate, has not been sufficiently insisted upon in trea-
taes on electricity. should not consider a metallic
ros, terminating without any snlargeme,t Of surface
IN The water or the EARTH SH dequute protection
against lightning; but were such conductors to ter
inmate IN talc Sheets buried in the earth or i'm
mersed IN the sea, or by onnection duly made with
the iron pipes, with which our city is watered or
the copper with which ships generally sheathed
should have the most perfect confidence in their
conpetes ey.
IL is not only important that the points of contact
6etwe." tine metallic mass crnPiuy aora
ming an adequate PASSAGE and the earth water in
which it terminates, should be so multiplied as to
compensate for the inferior conducting power of the
earth water; but il is also necessary that the con-
iucting rod be as continuous as possible. When
are to be stationary as when applied 10
buildings, they should consist of pieces screwed
ogether, or preferably joined by solder as wei as
" screwing. Where Aexibility is requisite, the |
ons should be neatly made like those Of the irons
fall top carriages; and should be riveed SO as TO
insure close contact at the June lures. .Ir
In all eases, the ordinary, but important precau-
ION OF having the rod TO terminate above in a fine
lean point, should be attended to- Where platina
Ups cannot be paid, multiplying the points by split
ing the rod into n rami6cation OF pointed wires,
nay compensate for the diminution Of conducting
over, arising from rust
The efficacy of the point or points, is, however
ependsnt the continuity OF the conductor of
'hich have already spoken since IL is well known
nat IL pointed rod be cut into parts, 40 as TO pro
uce intervals, bounded by blunt Examinations, its
fhcacy will not be much greater than ID il had no
ONT; because the fluid will in that case, pass in
parks, instead Of being transmitted in current II
on this account that object TO chains, or rod.
'heu by loops or hooks ana eyes. The error III
Imposing that metallic rod must be more capable
attracting electricity iniuriously, because OF its
nown wonderful power in transmitting IL, will be
vident when il Is understood that the only DIFF |
,rence between metals and other bodies arises from
he superior power Of transmission. Hence, when
a defective communication with the earth or sea |
ne efficacy Of the metal, conductor is diminish,
d, or destroyed, its Influence over charged cloud
proportiOBably lessened IL follows, therefore
rat far as II acts, its action must be bene
Mess its lower termination should by an isconceiy
lie degree of ignorance inaentoD, be so situated
10 render IL more easy for the electrical fluid 20
ave the rod, and pass through n portion of the>I ,
'use or vessel, than to proceed, by means Of the
d, into the earth or sea. &
Thus, Richmsn was killed Dy conductor which
employed to receive electricity from the clouds
ID 10 convey % to am eectrometer, essarily In.
lated: under these Circumstances, the head Of the
o'essor eing about foot from the conduct he
came part OF the channel of commit mic alton with
c earth. Had the apparatus been surrounded bv | 4
&c Of wire, and this duly connected with a metal
rod, soldersd 10 a sheet Of metal buried in the
nh, Richman might have made his observations h
perfect security. That, with due precaution y
eriments analogous TO his are not productive OF h
nv TO the opera or, is rendered evident by the p
Joined quotst from Singers Electricity ,
must premise, that the apparatus, by means Of r
eh the phenomena alluded 20 were proc ced con. n
ID OF a wire mile long, supported, and nsulsed a
tvery high poles, and terminating in the house OF
Electrician, Andrew Crosse, Esq.
he approach of a charged cl-ud produces some. y
Y positive, aud at others negative signs, at FIRST:
brhstever he the original character the effect II
gally increases 10 a certain extent, then de. 81
chs. and disappears aud - followed by the app Il
pace Of the opposite signs, which gradually OK Al
te,eyond the former maxirIum, then decrease, n
temte, aaj are again followed by the original :
sl.city. These alterations are sometimes nu- u
l.. A