Unpublished paper, 'On the disruptive discharge of accumulated electricity, and the proximate cause of lightning' by Isham Baggs

Description

Baggs investigates the 'principal causes of the violent and disruptive union of opposite electricities which constitutes the electric discharge', and attempts to apply the knowledge thus gained to the explanation of natural phenomena, and the further proof of the identity of frictional and voltaic electricities. He describes two instruments which he employed 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 dangers of fracture from an excess of charge.Baggs concludes 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 thickness, 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 coating of each with the inner coating of the next, is charged by means of an electrical machine, the tension 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 an 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 arrangement is charged with an electricity of an opposite kind to that of the knob adjacent to it, Baggs observes that the tension of the electricities was greatly augmented, giving rise to violent explosions whenever a discharge 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 electricity, alternately positive and negative, the central one having the highest intensity, and the tension diminishing in the successive zones surrounding the innermost, until it became inappreciable in the one most remote, Baggs considers this condition of the cloud to be analogous to that of the battery above described.

Annotations in pencil throughout. Followed by five pages of diagrams of Baggs' experimental setup.

Subject: Electricity / Meteorology

Received 28 October 1847. Communicated by Samuel Hunter Christie.

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 5 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'On the disruptive discharge of accumulated electricity, and the proximate cause of lightning'.

Reference number

AP/30/1

Earliest possible date

1847

Physical description

Ink and graphite pencil on paper

Page extent

35 pages

Format

Diagram
Manuscript