The casting of bronze was generally done by the _cire perdue_ method. A core of blackened sand is usually found in the casting. This was probably sand mixed with a little organic matter; as it is never reddened, probably no clay or mud was used. Over the core the wax was modelled, and the traces of the modelling tool can be seen clearly on unfinished bronzes. On an ibis there was a rolled pellet of wax put between the beak and the breast, so as to induce the flow of the metal along the beak; this would be easily cut away in finishing. An example of a kneeling figure shows the legs completely modelled before putting the pleated dress over them, and then the whole was cast. How the core was fixed within the outer mould is a difficult question. On the many unfinished bronzes that I have examined I have never found a definite connection above the base, but only casual blowholes. Yet the metal was often run as thin as ⅟₅₀th so that a shift of the core by as little as ⅟₁₀₀th inch would throw the casting out, and make a flaw. How the core was retained so firmly in position against the flotation of the melted metal is not clear. No metal bars were put through the core to steady it, as Cellini did in his large castings. A system was used of stiffening bronze-work by casting it over iron rods; by the free use of iron, this must be of the Greek period. Solid bronze castings come into use in Ptolemaic and Roman work. A favourite decoration of copper-work in later times, from about 700 B.C., was by inlaying lines of gold or silver in it. This is a common system in India now, where it is known as _Keft_ work; the name suggests that it was introduced from Egypt, where Keft was the starting-point of the Indian trade route from the Nile. One of the finest examples of this is the statue in the Athens Museum (figs. 111, 112); another is the hawk-head and collar with the name of Aahmes II in the British Museum. The lines were first chiselled or punched in the copper, and then the gold was beaten into the grooves. No instance of using soft solder to copper or bronze is known till Roman times. Lead is found in the prehistoric times in the form of small figures and little objects; it was probably brought from Syria. It next appears as a rather common metal in the XVIIIth dynasty, when net-sinkers were generally made by bending a piece of sheet lead round the edge lines of the net, much as at the present day. In the filling of bronze weights it is found both in the XVIIIth and XXVIth dynasties. And an alloy of copper and lead--now known as pot-metal--was commonly used for statuettes in Greek and Roman times. In Coptic times pewter bowls and ladles were made; the bowls are apparently formed by spinning.