The oldest seals that have been discovered in Egypt are of cylindrical shape, hence their name, cylinders, or more correctly, cylinder-seals. They range in size from half an inch to three and a half inches in length, and from a quarter of an inch to three quarters of an inch in diameter. They are pierced longitudinally with a hole, the diameter of which varies from a size just sufficient to receive a small thread of linen, to an aperture in which an ordinary sized finger can be thrust. The two ends are always quite plain, the engraving, in intaglio, being confined to the convex surface, which, as a rule, is parallel to the axis. In some specimens, however, the surface is hollowed in such a way that the diameter of the cylinder is greater at the ends than in the middle, but such cylinders are rare, and generally show traces of nearly erased signs appearing through the engraving; they must therefore be considered as having had their original inscription ground down in order to be re-engraved with other characters; they are in fact cylinders that have been re-used. [Sidenote: How used.] When the cylinder seal was required for sealing, it was gently but firmly rolled over the soft clay or other substance destined to receive the impression. To make a good and continuous sealing with an unmounted cylinder is not, however, an easy matter, and consequently we find that this class of seal was often mounted by inserting a rod of metal through its aperture, the ends of which rod projected from the cylinder, so that it could be easily held by the forefinger and thumb, while the rod, serving as an axle, enabled the operator to keep the seal in place, and at the same time to preserve an even pressure whilst rolling it over the clay. This metal rod was sometimes finished off at one end into a kind of boss, while the other end was coiled round to form a loop, so that the cylinder might be attached to a necklace or string (fig. 17). The cylinder seals of kings and nobles had more elaborate mountings, and their ends were often encased in gold, as in a specimen found by Dr. Reisner near Girgeh, and as in an example figured in a Fourth Dynasty tomb at Medûm (fig. 18). Another method of mounting is shown in a hieroglyph (fig. 19) from a Fifth Dynasty Tomb at Sakkara. Here the cylinder appears to be mounted on a metal rod, the projecting ends of which were fixed to either side of a small frame, with a handle in which the cylinder seal could revolve. By holding the handle and dragging the cylinder over the clay to be impressed, the seal would revolve as easily and evenly as a wheel on its axle, and consequently leave a good and firm impression behind. The greater number of cylinders, however, are found without any trace of having been mounted, and as many show signs of wear on the edges inside the hole, we may conclude that they were generally simply threaded on a cord, which, for security sake, was