Guards were placed to watch the dykes which protected the lowlands, and the utmost care was taken to prevent any sudden influx of water which might endanger the produce still growing there, the cattle, or the villages. And of such importance was the preservation of the dykes that a strong guard of cavalry and infantry was always in attendance for their protection; certain officers of responsibility were appointed to superintend them, being furnished with large sums of money for their maintenance and repairs, and in the time of Romans any person found destroying a dyke was condemned to hard labor in the public works or in the mines, or was branded and transported to the Oasis. According to Strabo, the system was so admirably managed, "that art contrived sometimes to supply what nature denied, and, by means of canals and embankments, there was little difference in the quantity of land irrigated, whether the inundation was deficient or abundant." "If," continues the geographer, "it rose only to the height of eight cubits, the usual idea was that a famine would ensue, fourteen being required for a plentiful harvest; but when Petronius was præfect of Egypt twelve cubits gave the same abundance, nor did they suffer from want even at eight;" and it may be supposed that long experience had taught the ancient Egyptians to obtain similar results from the same means, which, neglected at a subsequent period, were revived, rather than, as Strabo thinks, first introduced, by the Romans. In some parts of Egypt the villages were liable to be overflowed when the Nile rose to more than an ordinary height, by which the lives and property of the inhabitants were endangered, and when their crude brick houses had been long exposed to the damp the foundations gave way, and the fallen walls, saturated with water, were once more mixed with the mud from which they had been extracted. On these occasions the blessings of the Nile entailed heavy losses on the inhabitants, for, according to Pliny, "if the rise of water exceeded sixteen cubits famine was the result, as when it only reached the height of twelve." In another place he says, "a proper inundation is of sixteen cubits * * * * in twelve cubits the country suffers from famine, and feels a deficiency even in thirteen; fourteen cause joy, fifteen security, sixteen delight; the greatest rise of the river to this period being of eighteen cubits, in the reign of Claudius; the least during the Pharsalic war." The land being cleared of the water, and presenting in some places a surface of liquid mud, in others nearly dried by the sun and the strong northwest winds (that continue at intervals to the end of Autumn and commencement of Winter), the husbandman prepared the ground to receive the seed, which was either done by the plow and hoe, or by more simple means, according to the nature of the soil, the quality of the produce they intended to cultivate, or the time the land had remained under water.