Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/93

 4 feet in thickness. This is sufficiently hard to resist the action of the weather, and, to a certain extent, it protects the softer gypseous marls and shales underneath. As the waste of the latter still goes on, the blocks of conglomerate gradually lose their support and fall down, leaving a conical hill, which is then rapidly destroyed, unless a fresh conglomerate is formed in place, as frequently happens, owing to the ready solubility of the cementing material — gypsum. In some places the gravel is from 15 to 20 feet thick ; but it sometimes happens that the pebbles disappear, leaving a bed of almost pure crystalline gypsum in its place. The pebbles in the conglomerate are almost all of Nummulitic limestone, of a dark-grey, black, or yellowish tint, and externally present the peculiar pitted and furrowed appearance caused by the scouring of drifted sand, which is so characteristic of all the loose stones found on the African and Arabian deserts. At c there is a low terrace of blown sand; and from this point to the shore worn shells and branches of coral abound, increasing in quantity towards the beach. From c to the foot of the hill they are almost entirely absent, only a single valve of a Pecten having been found between the former point and the region of the conglomerate-hills.

The springs at Ain Mousa rise from the salt and gypseous shales, probably being fed by the drainage of the gravel-region at the back of them. There are 10 or 11 principal ones. The largest discharges into a basin about 30 feet in diameter, and shows a slight discharge of gas. There is a small deposit of bog-iron-ore in the basin, and, according to Heuglin, a great number of Diatomaceae are found in the mud. An upper spring, about 150 yards to the south of the gardens, crowned by a solitary palm tree, which forms a prominent and welcome land-mark to the traveller returning from the desert towards Suez, contains a great number of Cyprides also, which, together with the sand, form a basin round the point of discharge.

The height of Moses's Wells above high-water-mark is about 45 feet. Their aspect has changed considerably since the time of Heuglin's visit in 1861, when it appears to have been a place of residence for Suez merchants, as he speaks of having lodged in the villa of the Belgian consular agent. Nowadays there is nothing approaching to a decent habitation, although the enclosures have increased in number, the most pretentious being a miserable grog-shop rejoicing in the name of the Hotel de Bourgogne. The springs are now nearly all enclosed, even the higher outlying one on the hill having been in process of enclosure by a wire fence on our return in the month of June last (1868). At the same time it is also subjected to the incursions of visitors to a much greater extent than formerly, owing, no doubt, to the great influx of population at Suez and other points on the Isthmus, consequent on the undertaking of the canal from the Mediterranean to the Red Sea, and the new deep-water harbour for the Indian mail-steamers. A certain amount of rest must, however, have been given to the place since the cessation of the water-supply to Suez, which town, it need scarcely be said, is no

c 2