44 NORTH-WEST AFRICA. Such are the sands which encircle the date-palm plantations of Tripoli, and which are described by travellers as already forming part of the " great desert," although this region lies hundreds of miles distant, beyond the Jebel Ghurian. Along the shores of the Great Syrtis and of "Western Tripolitana the tides are so little felt that their existence has been denied by several observers, such as Delia Cella, Pezant, and even the experienced Captain Beechey. During syzygy the water rises about two feet, and occasionally, when impelled by fierce northern gales, as high as five feet. It is difficult to form an adequate idea of the enormous power exercised by the surf along the crescent- shaped shores of the Great Syrtis, which have at all times been dreaded by seafarers, and regarded by them as irresistibly attracting vessels to their destruction. According to Sallust, this very attractive force is indicated by the term SjTtis. Possibly, also, the terrible Lamia, that devouring monster said by the Greeks to dwell in a cavern on this seaboard, was nothing more in their eyes than the spirit of the storm and whirlwind. At Zafran, near the ancient Medineh-es-Sultan, the coast is fringed, as it were, by huge blocks, lashed and piled up by the waves in the form of breakwaters. At first sight they in fact present the appearance of the remains of colossal quays, although the vast development of these formidable sea walls shows that we are in presence of some work of nature. Nevertheless this natural structure had formerly been utilised as a support for an artificial pier erected to shelter the port of Zafran. The coast of Tripolitana is one of those where, right or wrong, indications are supposed to have been observed of a slow subsidence of the ground, or else of an upheaval of the sea-level. At Tripoli, the movement is said to have proceeded at the yearly rate of about half an inch during the last half century. Thus the Mediterranean would appear to be slowly but incessantly working gradually to recover its ancient inlets, which, although now dried up, still lie below sea-level. Climate. The climate of Tripolitana resembles that of the other regions along the North African seaboard, except that here the southerly deflection of the coastline gives it a higher average temperature, and on the whole a more continental character. The maritime district is comprised within the isothermals of 68° and 72° F., whereas in the interior the heat is higher on the low-ljaug districts, lower on the uplands. On the sands at noon it exceeds 154°, and even 170° F., and Rohlfs' dog had in some places to be shod with sandals before he could follow his master across the burning soil. According to the same traveller, the normal yearly temperature is as high as 86° F. in the Jofra oasis at the foot of the Jebel-es-Soda. But it should be added that these intense heats are far more easily borne in the dry regions of the interior than would be the case on the coastlands, where per- spiration is checked by the excessive atmospheric moisture. The impression pro- duced by the heat along the seaboard may be compared to that felt in a Turkish bath. Between the extremes of heat, exceeding 105^ and 112^ F., and of cold, the
