The Sun.
London, England, 1848-02-14 00:00:00

1848.

RECENT DISCOVERIES IN ELEC-
TRICITY.
[ln the:Literary Gazette of the sth instant, we find
the following synopsis of a very remarkable paper
recently laid before theßoyal Society; and we would
particularly direct to it the attention of--bur readers,
as it appears to us to be the announcement of one of
the most extraordinary discoveries yet made in elec-
tricity. Those who are at all familiar with the sub-
ject must be already aware that, for a very consider-
able time past, philosophy has been baffled in its re-
searches as to the actual cause of lightning. The
immortal Franklin had demonstrated the identity of
that sublime phenomenon and electricity, but the
manner in which such enormous volumes of electricity
were first generated, and then discharged, has hitherto
remained an almost inscrutable enigma. One hypo-
thesis after another has been advanced, but one after
another they have proved ineffectual in resolving this
magnificent mystery. Some philosophers have attri-
buted the phenomenon to a spark, and others to an
explosion, and the matter has long been vainly
investigated by such men as Mr. Roberts, as Mr.
Sturgeon, of the Military College at Addiscombe, as
Mr. Walker, the editor of the Electrical Magazine,
and as Mr. Snow Harris, the distinguished practical
electrician, whose lightning conductors have been
very generally and successfully adopted in the navy
of Great Britain. At length the proximate cause of
the enormous electrical discharges called lightning
seems to us to have been definitively discovered. The
discoverer—Mr. Isham I3aggs--has added another
great truth to those lately established and promul-
gated by Professor Faraday. He has, to our thinking,
solved one of the noblest problems of Nature, and has
proved, upon those august principles of philosophy
which were first maintained by Lord Bacon—that the
phenomenon of lightning is an explosion analogous
to that of a Leyden jar, the intensity being derived
from a consecutive arrangement of positive and
negative elements, an arrangement which has been
carefully noticed by Mr. Crosse as that existing in a
thunder-cloud. According to the report which we
here transcribe from the columns of our contempo-
rary the Literary Gazette, it would appear that the
opinion of Mr. Baggs has been fully corroborated by
his subsequent investigations.—En. Sun.]
ROYAL SOCIETY, JAN. 13.—The Marquis of
Northampton, President, in the chair.—" On the
Disruptive Discharge of accumulated Electricity,
and the Proximate Cause of Lightning," by Mr.
Isham Baggs ; communicated by Mr. S. Hunter
Christie, Secretary to the Royal Society. The author
proposes to inquire into the principal causes of the
violent and disruptive union of opposite electricities
which constitutes the electric discharge ; and to
apply the knowledge thus gained to the expla-
nation of natural phenomena, and the further
proof of the identity of frictional and voltaic electri-
cities. He describes two instruments which he em-
ployed for the purpose of regulating the discharges of
a Leyden jar, or battery, by adjusting with precision
the distances between two brass balls, forming a
communication between the inner and outer coatings ;
allowing of their being charged only to a limited
degree of intensity, by carrying off all the electricity
beyond that extent; and thus guarding the glass from
the danger of fracture from an excess of charge. He
is led to the conclusion, that with a given dialectric,
such as glass, the limit to the intensity of the charge
it can receive varies directly as the cube of its thick-
ness, being in the compound ratio of the resistance it
presents to the discharge, which is simply as
the thickness, and of the square of the
distance of the two charged surfaces, such
being the law of electric action. When a
number of insulated Leyden jars, arranged
in a consecutive series by connecting the outer coat-
ing of each with the inner coating of the next, is
charged by means of an electrical machine, the ten-
sion of the charge diminishes in each jar as they
follow in the series, that of the terminal jar being
exceedingly small. On the other hand, when each
jar has been charged separately in the same
manner and to as equal extent, and then
quickly arranged in a series, the jars not touching
one another, but the knobs connected with the
inner coating of each jar, after the first being
placed at a certain distance from the outer coating
of the preceding jar, which in such an arrange-
meat is charged with an electricity of an opposite
kind to that of the knob adjacent to it, the author
found that the tension of the electricities was greatly
augmented, giving rise to violent explosions when-
ever a di' charge occurred. He considers a battery
thus constituted as bearing the same relation to a
single Leyden jar as the voltaic pile does to a single
galvanic circle; and as affording in like manner the
means of exalting, to any assignable degree, the
electric tension. Adopting the views of Mr. Crosse
as to the constitution of a thunder-cloud, namely, that
it is formed of a number of concentric zones of elec-
tricity, alternately positive and negative, the central
one having the highest intensity, and the tension
diminishing in the successive zones surrounding the
innermost, till it became
,inappreciable in the one
most remote; the author considers this condition of
the cloud to be analogous to that of the battery above
described, and the phenomena of the former to receive
complete illustration from the experimental results
obtained with the latter.