To relieve the tedium of the topographical part of his work, Pausanias has introduced digressions on the wonders of nature and of foreign lands. Thus, for example, having mentioned the destruction of Helice by an earthquake, he describes the ominous signs which herald the approach of a great earthquake—the heavy rains or long droughts, in winter the sultry weather, in summer the haze through which the sun’s disc looms red and lurid, the sudden gusts, the springs of water drying up, the rumbling noises underground. Further, he analyses the different kinds of shocks, determines the nature of the one which destroyed Helice, and describes the immense wave which simultaneously advanced on the doomed city from the sea. He refers to the ebb and flow of the ocean, to the ice-bound sea and frozen deserts of the north, to the southern land where the sun casts no shadow at midsummer. He tells how the Chinese rear the silkworm, and describes both silk and the silkworm more correctly than any writer who preceded and than some who followed him. It has been suggested that he derived his information, directly or indirectly, from a member of the Roman embassy which appears from the evidence of Chinese historians to have been sent by the emperor Marcus Antoninus to the far East and to have reached the court of China in October 166 A.D. Again, he describes the Sarmatians of northern Europe leading a nomadic life in the depths of their virgin forests, subsisting by their mares, ignorant of iron, clad in corselets made of horse-hoofs, shooting arrows barbed with bone from bows of the cornel-tree, and entangling their foes in the coils of their lassoes.