MECHANICAL CHARACTERISTICS OF LIGHTNING STROKES.
At the first monthly meeting for the session of the Royal Meteorological Society, a paper was read by Colonel the Honourable Arthur Parnell on ‘The Mechanical Characteristics of Lightning Strokes.’ The main objects of this paper were—first, to attempt to show that lightning is not a sort of electric fluid that descends from the clouds, injures buildings and persons in its course, and dissipates itself in the earth; but that it is a luminous manifestation of the explosion, caused by two equal forces springing towards each other simultaneously from the earth and the under surface of the inducing cloud, and coalescing or flying out nearly midway between the two plates of the electrical condenser formed by the earth and the cloud; secondly, to demonstrate that of these two forces, it is the earth-spring or upward force alone that injures buildings, persons, or other objects on the earth’s surface, and that constitutes tangibly what is rightly known as a lightning stroke. The author gave the details of two hundred and seventy-eight instances, the records of which were intended to demonstrate with more or less precision the existence of an upward direction in the force of the stroke. The theory of the descent of the electric fluid was suggested a few years ago by M. Colladon, a French Professor, and a notice of it will be found in Chambers’s Journal for October 16, 1880.