Various causes of the great depression of the valley have been suggested, among which the action of glaciers has been one of the latest. M. Lartet, the French geologist, was, I believe, the first to point out the clear indications of a great fault or crack, extending all along the valley, which has, in fact, slid down towards the centre of the earth. Special observations were, however, much wanted, and we were able to supply these all along the western side, where apparently they were the most necessary. To enter into the details of these observations would be impossible in the present work. I propose to sum up the results which seem to me most important, and which I have submitted to geologists for criticism. The main reason for conjecturing the existence of a fault, is that the formations on the east and west are not the same. On the west we have strata of the age of the English chalk, which dip down very suddenly towards the centre of the valley. On the east we have the Nubian sandstone, with hard limestone above it geologically coeval with our greensand. The section of the present bed of the Dead Sea tells the same story; the deepest part is towards the east, where there is more than ten times the depth of water found near the western shore, and here the mountains rise almost sheer from the lake, while on the west, a succession of steps occurs between the sea and the watershed. The precise manner in which the slopes of the Palestine watershed fall towards the Ghôr differs in the different regions, but in principle it is the same throughout; there is everywhere a violent contortion of the strata, sometimes forming a fault or fissure running north and south, and sometimes a sharp dip down eastwards. We first studied the section above the Bukei’a, near Mar Saba, and here, as I have before noticed, there appears to be a well-defined fault. In the neighbourhood of Fusâil I found the rocks tilted up at an angle of 30°, and the same violent contortion has formed the great fissure of Wâdy el Hamâm, west of the Sea of Galilee. The Fâr’ah Valley is a great rent seemingly due to the same causes, and thus the whole of the geological evidence goes apparently to prove the occurrence of a violent and probably sudden collapse of the whole Jordan Valley commencing north of the Sea of Galilee.