enunciated. If a conoidal mass, of subjacent rock, be covered with deep earth, which is shaken partially down and commences to slip, the slippage will be in lines, radiating downwards the slopes, in all directions from the top, and the fissures must radiate from the top, like the rays of a star, being widest at the centre. Or, fissures with lips of unequal level, may form at different altitudes, in horizontal planes running round the sloping sides; or both such sets of fissures, may intersect each other; dependent upon the angle of slope of the rock, that of repose of the earth, its depth, and other circumstances; but all the phenomena due to mere shaking down and slippage.
Again, if from beneath one portion of a deep plain of earth or sand, the base of whatever sort, be lowered or partially removed, as when the roof of a limestone cavern (like that noticed at Campostrina) may fall in; or when water may be partially withdrawn, from unequally distributed quicksand, beneath, &c.; then, a shallow bowl-like hollow or depression will be produced, and fissures radiating from the centre as before, and, as before also, crossed or not by others, tending to the form of concentric circles, may result. This last was just the case described in the Academy Report of the plain of Calabria, about Jerocarne and Rosarno, &c.
The vulgar mind, filled from infancy with superstitions of terror as to "the things under the earth," is seized at once by the notion of these fissures of profound and fathomless depth, with "fire and vapour of smoke" issuing from within their murky abysses, but they should cease to belong to science.
Of actual landslips we had examples, at Carlotta D'Isca,
