Assuming that the conception of Lake Mœris, as given in this paper, is a true one, we have now to consider how the change to present conditions in the Fayûm came about.

In the passage quoted from ‘Hawara, Biahmu, and Arsinoë,’ Mr. Petrie states that “apparently under the Persians or Ptolemies the desire to acquire more land in the Fayûm at the expense of the irrigation of the Nile valley, led to restricting the inflow, and gradually drying up the lake.”

Mr. Cope Whitehouse, in one of his papers, points out that Mœris, in its character of regulator and reservoir, existed chiefly for remote provinces, and therefore required for its maintenance a strong central government with sufficient administrative skill and energy to take the necessary steps and to expend the necessary amount of money to secure the maintenance of the reservoir, canal, and regulators in working order. Under a careless government, or while anarchy, or internal or external troubles weakened administration, the private interests of individuals who were on the spot to assert themselves, would have prevailed over the public claims of the Northerners, powerless to keep watch over and to insist upon their rights from the distant towns of the Delta. A corrupt Public Works Department, uncontrolled by a chief with broad views of what was desirable in the general interests of Egypt, may have permitted each chief engineer of a nome to do what seemed good in his own eyes for the profit of the particular part of Egypt in which he was the Public Works officer. If we imagine that he had scruples, there have not been absent, in the modern history of the Irrigation Department of Egypt, instances of the application of means for overcoming scruples, and, as so much else in the customs of the country can be traced back to that far past time when Lake Mœris must have been languishing towards extinction, we may also suppose that the Eastern salve for tender consciences was applied and the scruples overcome.

But whatever the cause (and there is nothing but speculation, which can help us to imagine it), at some time or other, either by a gradual or sudden process, Lake Mœris ceased to perform its offices of regulator and reservoir, which had won for it the admiration of all who visited it. Having once reached the stage when it ceased to be useful in supplementing the low Nile, there would be nothing to prevent measures being taken to exclude all water, but such as was necessary for the irrigation of the reclaimed areas. Evaporation would lower the Lake level year by year, and leave more land uncovered. Year by year the Lake would contract itself, and retire to lower levels, until it had reached the present dimensions of the modern Lake Qurûn, whose water surface at the commencement of May 1892 was 43·50 metres below mean sea-level. The rate of the lake’s retreat was doubtless not uniform and continuous, but was retarded by accidents and breaches of the barrier, raised against the Nile floods, causing a return of the water over reclaimed lands. The deep ravines of the Fayûm are nature’s bold strokes on the face of the province, which record some of the victories of the water, in its efforts to fulfil the law imposed on it to find its own level, over man’s endeavours to control this law.

Evaporation by itself, had its results not been vitiated by other causes, would have lowered the lake surface by about 2 metres a year, but the drainage and waste from the reclaimed area under irrigation would have retarded the fall, and breaches would probably have occasionally converted the fall into a rise. It is therefore difficult to assign dates for different levels of the lake surface, but probably the old towns at different levels around the borders of the Fayûm, so far as their dates can be fixed, will, when their levels have been correctly ascertained, throw some light on this subject.

The former manner of conducting the irrigation of parts of the province would have caused a much larger proportionate discharge into the lake, than finds its way to it at present. Considerable areas were enclosed by banks, and inundated under the Basin system, known in the Fayûm as “Malaq,” in contradistinction to irrigation by small field channels, a system called “Misqâwi.” The contents of these small basins, when emptied, flowed into the lake. On the south side of the Fayûm there was, until late years, a large basin known as “Hod-el-Tuyûr” (the Basin of the Birds), which was formed by building an immense wall across a fold of contour R.L. 15·00. The top of this wall is about R.L. 16·00. The bed of the basin is at R.L. 12·00, so we may conclude that, when this wall was built, the lake levels must have been at any rate below R.L. 12·00. This basin was abolished in 1886, and ordinary perennial irrigation introduced over the area formerly included within the basin limits. Since then the fall of the lake surface has been more rapid, in spite of its annually diminishing evaporating area.

The existing lake, which is the rudiment of the large lake that once filled the whole of the Fayûm depression, is called Lake Qurûn, or el-Qurn, the Lake of the Horns, or the Horn, apparently so named from a rock that projects into the lake from its west side and called “el-Qurn.”

It is evident, from the levels of the rock bed underlying the Nile deposit near Hawârah, that the original course of the waters flowing into Lake Mœris (after it became Lake Mœris by introducing means of controlling its waters) must have been along the ravine which runs to the north of the modern village of Hawârat-el-Maqta. The bed of the present Bahr Yûsuf, at a point about a kilometre below that village, is rock at R.L. 21·00, and this rock joins the high desert on the south of the Bahr Yûsuf. But on the north it dips down, and close under Hawârat-el-Maqta has been found to have its original surface at R.L. 19·17, dipping still lower towards the north-east. [Plate XXV.] gives cross-sections of the entrance valley of the Fayûm, and also of the ravine behind Hawârat-el-Maqta.

“Hawârat-el-Maqta” signifies “Hawârah of the Breach,” and round about this village lay the battlefields where many a struggle was made by man to get the mastery of the water, until he at last prevailed. Massive walls and solid banks, retaining the Bahr Yûsuf in its high level channel, and barring the passage into ravines, scoured out by previous torrents of water bursting away from control, mark the sites of many a breach, and suggest sleepless and anxious nights of hard labour for the wretched irrigation officer in charge in the days when the water seemed to have asserted its rights to flow where it pleased.

On the left of the Bahr Yûsuf are the remains of a channel, which was clearly a temporary one for carrying the water, while a breach near Hawârat-el-Maqta was being repaired. Linant Pasha tells of the occurrence of one of these breaches on the west of Hawârat-el-Maqta as late as the commencement of this century (in 1819 or 1820). He states that this breach caused much damage. An attempt was made to close it during the floods, but in spite of all that could be done, and in spite of the energy of the people employed by Mehemet Ali, it was not till after six months at the time of low water that the closure was effected. It appears that the old bridge at Lahûn (the only one existing at the time) could not be closed, when the breach occurred, probably for want of suitable closing apparatus. This breach was down-stream of the rock bed in the Bahr Yûsuf.