The tomb of Zet consists of a large chamber twenty feet wide and thirty feet long, with smaller chambers around it at its level, the whole bounded by a thick brick wall, which rises seven and a half feet to the roof, and then three and a half feet more to the top of the retaining wall.  Outside of this on the north is a line of small tombs about five feet deep, and on the south a triple line of tombs of the same depth.  And apparently of the same system and same age is the mass of tombs marked W, which are parallel to the tomb of Zet.  Later there appears to have been built the long line of tombs, placed askew, in order not to interfere with those which have been mentioned, and then this skew line gave the di-rection to the next tomb, that of Merneit, and later on to that of Azab.  The private graves around the royal tomb are all built of mud brick, with a coat of mud plaster over it, and the floor is of sand, usually also coated over with mud.

[Illustration:  372.jpg TOMB OF ZET, CIRCA 4700 B.C.]

The first question about these great tombs is how they were covered over.  Some have said that such spaces could not be roofed, and at first sight it would seem almost impossible.  But the actual beams found yet remaining in the tombs are as long as the widths of the tombs, and therefore timber of such sizes could be procured.  In the tomb of Qa the holes for the beams yet remain in the walls, and even the cast of the end of a beam, and in the tombs of Merneit, Azab, and Mer-sekha are posts and pilasters to help in supporting a roof.  The clear span of the chamber of Zet is 240 inches, or 220 if the beams were carried on a wooden lining, as seems likely.  It is quite practicable to roof over these great chambers up to spans of twenty feet.  The wood of such lengths was actually used, and, if spaced out over only a quarter of the area, the beams would carry their load with full safety.  Any boarding, mats, or straw laid over the beams would not increase the load.  That there was a mass of sand laid over the tomb is strongly shown by the retaining wall around the top.  This wall is roughly built, and not intended to be a visible feature.  The outside is daubed with mud plaster, and has a considerable slope; the inside is left quite rough, with bricks in and out.

Turning now to the floor, the basis of it is mud plastering, which was whitewashed.  On that were laid beams around the sides, and one down the middle:  these beams were placed before the mud floor was hard, and have sunk about one-quarter inch into it.  On the beams a ledge was recessed, and on this ledge the edges of the flooring planks rested.  Such planks would not bend in the middle by a man standing on them, and therefore made a sound floor.  Over the planks was laid a coat of mud plaster.  This construction doubtless shows what was the mode of flooring the palaces and large houses of the early Egyptians, in order to keep off the damp of the ground in the Nile valley.  For common houses a basis of pottery jars turned mouth down was used for the same purpose.  A very striking example of this method was unearthed at Koptos.