THE TOMBS OF THE CALIPHS.

From the Citadel our friends went to "the Tombs of the Caliphs," which extend along the east side of the city, and are conveniently reached by the Bab-el-Nasr. They are supposed to be the burial-places of the caliphs or sultans who ruled from the thirteenth to the sixteenth century. Some of them are or were magnificent structures, while others are comparatively plain in appearance. Down to the beginning of this century they had large revenues for keeping them in repair, and were guarded by the descendants of the sheiks and their followers, who had charge of them during their days of glory. Their revenues were taken away by Mohammed Ali, and since the time of that ruthless despot the custodians of the tombs have lived by what they could beg from visitors. Beyond the Citadel is a similar necropolis, called "the Tombs of the Mamelukes."

Evidently the buildings were erected, in most instances, without regard to cost, and before they began to decay they were to be ranked among the triumphs of Moslem architecture. Some of the domes and minarets are still magnificent, particularly those marking the resting-place of Sultan Barkuk and Keit Bey. The latter is considered the finest of all, and is the one most frequently drawn or painted by artists.

THE TOMB OF KEIT BEY.

The boys paid a second visit to the tomb of Keit Bey, and carried along their sketching materials. They found the architecture more difficult to represent than they had supposed, and Frank made two or three attempts at the graceful minaret before he succeeded in satisfying himself. The minaret is one of the finest in Cairo; it rises from a corner of the building, and has three stages or balconies, which diminish as they approach the top. The summit is shaped like a pear, and is usually disfigured with poles, from which flags are hung on days of festivals. The dome bears a marked resemblance to that of the Taj Mahal at Agra, in India, and terminates in a sharp spire instead of the conventional half-moon that generally surmounts a Moslem edifice. While Frank was busy with the structure, Fred made a sketch of several camels that were halted in front of the famous mausoleum, and the work of the two youths was afterward united into a single picture.

An early day was devoted to the Museum of Egyptian Antiquities at Boulak, a suburb of Cairo, and practically a part of the city. An excursion was made to Old Cairo, and from there by ferry to the island of Rhoda. On the latter is the famous Nilometer, or instrument for measuring the depth of water in the Nile; it is a square well, connected with the river, so that the water can freely rise and fall within it. In the centre of the well is a stone column, marked like a scale, with the old Arabic measures: the dra, or ell, was the unit of measurement, and was 21-1/8 inches in length, divided into 24 kirat. The height of the column is 17 ells, or about 30 feet, and the Nile at its lowest point covers about 7 ells of this length. When the water mounts to 15-2/8 ells the river is considered full, and the whole valley of the Lower Nile can be inundated. The embankments that restrain the water are then cut with a great many ceremonies, and the prospect of an abundant harvest causes general rejoicing.

Doctor Bronson explained to the youths that the taxation each year was based on the height of the water at the inundation, and the Nilometer was the official evidence of the condition of the river. Inscriptions on some of the monuments show that the ceremonies of cutting the banks were established as early as the fourteenth century before the Christian era, and the taxation was based on the height of water in ancient times as at present. The Nilometer was exclusively in charge of the priests, and the people were not allowed to see it. It was the object of the authorities to tax the people as heavily as possible, and there is good reason to believe that the priests made false statements concerning the height of the water, and no one could contradict them. The Arab and Turkish rulers did the same thing, and the practice is continued to the present time; at the period of the inundation the Nilometer is closed to the public, and every one must depend upon the figures of the officer in charge. As he owes his position to the government, it is pretty certain that he does what the government desires, and reports the river at the highest figure whether it is so or not.

The guide pointed out the spot at the end of the island where the infant Moses was found by the daughter of Pharaoh. The boys thought the place was pretty enough for the historical event to have occurred there, but were in some doubt as to the correctness of the guide's information.