New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1850-08-21
NEW-YORK TRIBUNE.
SCIENTIFIC CONVENTION
AT NEW-HAVEE
American Association for the Advancement
OF Science.
IReported for TIE Tribune.

NEw.HAvEN, Monday Evening, Aug.

NEw.HAvEE, Monday Evening, Aug. 10.
In my notice of Pro- OLnsTED's paper on Points
Of Electrical Theory, was obliged to stop with
the announcement Of the third point leaving the re-
msiDing two and the debate which followed their
introduction untouched.
In regard to the Returning Stroke Of an electri.
cal discharge, Prof o. related some interesting
particulars Of cases which had come TO his know.
edge. Among the numerous instances that occurred
10 lel3 Of houses Of public worship struck by light
ming he had known two; enc at Avon and the other
ut Stamford Connecticut In these cases there
were strong Indications that the charge came from
TIE earth. 10 both cases the meeting houses were
furnished with rods which appeared to have a.
forded partial but not entire protection to the build
ipgs. From the base Of each rod a large quantity
Of mud was thrown up the rod, covering 1t as high
as the cave, Of the house The Professors hyPo-
thesis to account for this action wa, this that upon
the charge descending the rod and reaching the
wet surface Of the earth the electricity woald es
cape freely from the rod, and the muddy surface OF
the earth around the base Of the rod would become
highly electrified The particles Of mud would thus
be rendered mutually and strongly fepalsige OF
each other, and tend 10 be dispersed on all sldes
but, having no freedom OF hc'loh ia Any O'uoi VI
Yeo.ioD, they would appear ~ be only thrown up
ward.
Trees Struck by LigAtaiag This was an In
terestiDs point in Prot OlmsEeds paper and eX'
cited coEIiderable discussion. be commented upon
the popular impression in the Southern part oil the
Unun that PIne trees are oil all trees the most apt
40 he struck by lightning, and this not merely Dc
eau.e in certain districts Pneiorests are the most
extensive OF any, but even, when mlXed WIN
ether trees Of the forest, the Pine seems most re-
auently assailed, when IT'S resinous cha' So'e'
xonld lead US 10 expect for 1t an exemption from
,t,cks The Professor held ~ the TACT that the
pine is proba bly, not more liable 10 be struck than
other trees perhaps not 80 liable out "heh S'rucA
Texbibns greater marks OF violence IN consequences
of its nor. conducting qualities since tue A'teH'ou
ID Prot 0lmsted was hr't dra"Ato 51'' su2IeeL 10
Ia. ob,etyed many facts ia re.@snt IN inc "sehsty
Of ,rse. to he struck with lightning, and has been
led to believe that this Is much more ,.equen'
occurrence than is generally supposed. ouch An
Inference might be drawn from tue humoe'o' N'eS'
both of men and animals, that are every .yeM
destroy ed by taking shelter under tfees during
thsnSer storm In most cases where trees are
INN Of am or are wet with rain, they are sacn good
conductors az TO transmit the charge without re-
oordips any marks Of violence. la other cases. the
sudden decay aud death of trees, wtoout any
other apparent cause, sugseits PfooaO'l'y 'nA'
liebtning may have been the true cause and We
NAV not unirequently trace the ELECTS oil eieo'
trici,y upon the trunks OF trees
/, has been question Of long standing whether
trees rowing near a house Afford II any ueSfee oi
protection. This question was considered ofieuy
Nv the Professor. The trees, he remarked, oelnS
usuany 10 q state which renders lhem Deter OOn
duotofs of electricity than the materials toat CON
nose buildings, and rising above the level o. the
latter, and presenting IN their leaves and terminal
branches numerous conducting points, they seem
peculiarly adapted TO act the part OF na'ura1 lleht
ming roos
The subject Of this psper excited general dis
sussioo, the leading points Of which arc briefly
matched below. The debaters were Msssrs HES
ny. LOOMS, OLhsrED, BRocKLEsBT and otner'.
Prof. Henry mentioned IA inStancs Of the ex.
panson of air during the passage OF an electrical
aischMee through house, through which TACT ne
had been led to the same conclusions on 1hs point
with Prof Olmsted. He had made aseries OF ex'
periments to ascertain whether the hyPothesls
was true or not The results we're attained oy
means Of Kimmersley's Air Fherm0mster, one oil
which was brought forward In Illustration. Toe
Professors investigations convinced MIN toat the
effect was due To ms repRlssbility. He cited sew
cral instances, some Of which were noticed BY him
,elf At Pripcetop where one roof was bio sn of aud
the aide Of another house blown oot De consd-
cred that the great mechanical ELECTS OF an elec.
sricsl discharge are due not 80 much 70 mechiaicA
,aorts az 10 the repulsive power OF the air. He
had made some interesting experiments Ia sAlvan
hp, whose effects he referred 10 tae same cause
Prof LooMls-In reply to the remarks OF Prof
Oinsted, regarding the common impression OF the
South that pise.tees are not struck by lightning
Prof Loomi, bad few words TO offer. BE men
toned similar important principle in Ohio, which
10 perhaps more general-thal the Beechtrees are
never struck This was prevalent idea. which
its quite dangerous 70 deny. But IN one Instance,
70 Prot L. knoSleoge, = beech tree was struck
by lightning. he Considered that where trees are
full OF sap they are IN much less danger; when
there II less sap they are more freq1eniy at
Tackled Dry trees are more shattered and retain
che MARKS.
Prof JOHNSON Gave instances Of ths elscsric
current describing spiral course; fAloxins a. !,
were. the grain Of the wood.
Prof BkocKLkSBT-Had had the piea,u,e II
pleasure il might be oAllej, OF being 10 the house
ut Avon wi en- IL wsE struck. Toe lishsnias apn,
rsnty came down tbs rod, bat this was Improperly
constructed. IDsteado OF beiog coatinued into the
earth for considerable depth, its lover extremity
entered the coil bat loar inches. from which point
ssahpieos Of pig iron were laid at dstances
tee', entirely detached from each Olber-,srmlnst-
hs az g bole Of TIE size OF maas hat TIE mud
vss thrown up 10 the big bit OF tbs oornioes, some
or % teet. Prof b. also oeservei some remark.
As'e appearances Of scOrcbed grass in the imaedl