At Cairo the Nile begins to rise about the third week in June, and the beginning of the overflow coincides with the heliacal rising of the Dog Star. The heavens have been called the clocks of the Ancients, and, according to some writers, it was the connection between the rise of the Nile and that of the Dog Star that first opened the way to the study of astronomy among the ancient Egyptians, so that not only was the Nile the creator of their country, but also of their science. The fellahs, however, still cherish a lingering belief in the supernatural origin of the overflow. They say that a miraculous drop of water falls into the Nile on the 17th of June, which causes the river to swell. Till September the river continues to rise, not regularly, but by leaps and bounds. In this month it attains its full height, and then gradually subsides till it reaches its normal height in the winter months. As is well known, the quality of the harvest depends on the height of the annual overflow--a rise of not less than eighteen feet at Cairo being just sufficient, while a rise of over twenty-six feet, or thereabouts, would cause irreparable damage. It is a common notion that a very high Nile is beneficial; whereas an excessive inundation would do far more harm to the country than an abnormal deficiency of water. Statistics show conclusively that most of the famines in Egypt have occurred after an exceptionally high Nile. Shakespeare, who, we know, is often at fault in matters of natural science, is perhaps partly accountable for this popular error:--"The higher Nilus swells, the more it promises," he makes Antony say, when describing the wonders of Egypt to Cæsar. [Illustration]