LANDSLIPS, large portions of land which from some cause have become detached from their original position, and slid down to a lower level. They are especially com mon in volcanic districts, where the trembling of the earth that frequently accompanies the eruption of a volcano is sufficient to split off large portions of mountains, which slide down to the plains below. Water is another great agent in producing landslips. It operates in various ways. The most common method is when water insinuates itself into minute cracks, which are widened and deepened by its freezing in winter. When the fissure becomes sufficiently deep, on the melting of the ice, a landslip is produced. Sometimes, when the strata are very much inclined, and rest on a bed susceptible of absorbing water, and becoming slippery, the superincumbent mass slides over it to a lower level. This took place on a large scale in Dorsetshire between Lyme and Axmin ster, in 1839, an unusually wet season, in which the strata had become saturated with moisture. A mass of chalk and greensand here slid over the slippery surface of a bed
of liassic clay down into the sea, leaving a rent three-quarters of a mile long, 240 ft. wide, and 150 ft. deep. Of the same kind was the slip of the Rossberg, in Switzerland (see GOLDALT). Landslips of a different kind have been produced in peat-mosses, which becoming by heavy rains thoroughly saturated with water, have burst their natural boundaries, and discharged themselves on a lower level. The most remarkable case ou record is that of the Solway Moss, which, in 1772, owing to greater rains than had fallen for 'nearly two centuries, spread itself in a slowly rolling, resistless deluge of black mud over 400 acres of cultivated fields, and to such a depth as almost to cover several houses, while it reached the roof of others.