The mirage--Skirmishes with the Arabs--Mistake of General Desaix's division--Wretchedness of a rich sheik--Combat beneath the General's window--The flotilla on the Nile--Its distress and danger--The battle of Chebreisse--Defeat of the Mamelukes--Bonaparte's reception of me--Letter to Louis Bonaparte--Success of the French army-- Triumphal entrance into Cairo--Civil and military organisation of Cairo--Bonaparte's letter to his brother Joseph--Plan of colonisation. On the 7th of July General Bonaparte left Alexandria for Damanhour. In the vast plains of Bohahire'h the mirage every moment presented to the eye wide sheets of water, while, as we advanced, we found nothing but barren ground full of deep cracks. Villages, which at a distance appear to be surrounded with water, are, on a nearer approach, discovered to be situated on heights, mostly artificial, by which they are raised above the inundations of the Nile. This illusion continually recurs; and it is the more treacherous, inasmuch as it presents to the eye the perfect representation of water, at the time when the want of that article is most felt. This mirage is so considerable in the plain of Pelusium that shortly after sunrise no object is recognisable. The same phenomenon has been observed in other countries. Quintus Curtius says that in the deserts of Sogdiana, a fog rising from the earth obscures the light, and the surrounding country seems like a vast sea. The cause of this singular illusion is now fully explained; and, from the observations of the learned Monge, it appears that the mirage will be found in almost every country situated between the tropics where the local circumstances are similar. The Arabs harassed the army without intermission. The few wells met with in the desert were either filled up or the water was rendered unfit for use. The intolerable thirst with which the troops were tormented, even on this first march, was but ill allayed by brackish and unwholesome water. The army crossed the desert with the rapidity of lightning, scarcely tasting a drop of water. The sufferings of the troops were frequently expressed by discouraging murmurs. On the first night a mistake occurred which might have proved fatal. We were advancing in the dark, under feeble escort, almost sleeping on our horses, when suddenly we were assailed by two successive discharges of musketry. We aroused ourselves and reconnoitred, and to our great satisfaction discovered that the only mischief was a alight wound received by one of our guides. Our assailants were the division of General Desaix, who, forming the advanced guard of the army, mistook us for a party of the enemy, and fired upon us. It was speedily ascertained that the little advanced guard of the headquarters had not heard the "Qui vive?" of Desaix's advanced posts.