LIGHTNING.

New Zealand Colonist and Port Nicholson Advertiser, Volume I, Issue 34, 25 November 1842, Page 4

LIGHTNING.

On Tuesday evening se’nnight a paper on lightning conductors, in connexion with the accident at Brixton church, was read at the meeting of the London Electrical Society. Its author, Mr. Walker, the secretary of the society, had made a survey of the damage done to the tower of Brixton church, and found in it so practical an illustration of Dr. Farady’s opinion on the “ literal discharge,” as to induce him to investigate the subject more closely. It seems that no arrangement of metals could have been better adapted than that met with in this steeple to invite a flash of lightning to do mischief. There was a regular series of stepping-stones, as it were—first, an insulated metallic cross, then 20 feet of stone work; in passing this interval the roof of. the lantern was shattered: then come 20 or 30 feet of conductor, in the form of the clock wire, and a water-pipe; and then a break of 12'' feet. Here, again, was an explosion, and an immense mass of masonry was shattered away from the base of a column intervening between the termination of the water-pipe and the commenceof the next series of conductors. Within the belfry “ a lateral discharge” took place; the

fluid passed from one conductor to a vicinal , one, for no other reason than to obtain a wider The author showed that electricity riot orily chooses a short but also a wider path : and that the “ lateral spark” arises from the latter property. He then explained that it is not enough to have a continuous or an insulated lightning rod, but it is most important to have it far away from other metallic bodies ; for however capacious the rod may be, and however adapted to convey, not only what passes down it, but ten thousand times more, yet, if another conductor is near, a flash will pass between the two, and ignition of neighbouring combustibles will be the result. Fortunately, in the case in question, only a small part of the whole fluid passed within the tower, consequently the lateral explosion was not severe. As it is not always possible to place lightning rods entirely out of the neighbourhood of other conductors, Mr. Walker showed that the possibility of the fluid’s passing between them should then be converted into a certainty, by making metallic communication between them, and thus tracing out a path along which the fluid might pass without the development of light and heat. He spoke of the peculiar property of the points of leaves, twigs, &c., in drawing off quietly charges of electricity, and stated his conviction that tall trees would always be found valuable, if not in entirely averting, at least in greatly mitigating, the force of a lightning shock. The theoretical opinions given in chis communication were based upon the experiments of the Royal Institution, the object of the author being to show how closely they were illustrated on the grand scale of nature, and to direct the attention of the public generally to a closer study of the properties of lightning-rods, a subject on which, perhaps more than on any other practical point, more ignorance prevails than can be well conceived.