B.C.), and exhibited with that sarcophagus in the Terracotta Room, and the beautiful bronze ornamental strigil in the Bronze Room (Pedestal 3), with the handle in the form of a girl herself using the strigil. A complete bather's outfit of Roman date (No. =337=), found near Düsseldorf, includes two bronze strigils and an oil-flask attached by rings to a handle (fig. 126), and several glass vases for use in the toilet. [Illustration: FIG. 127.--SECTION OF ROMAN BRONZE PUMP FROM BOLSENA (NO. 338). 1:5.] =Water Supply.=--A few objects in Cases 38-39 illustrate the methods of water-supply among the Romans, which are characterised by their completeness and excellence. The remains of two Roman double-action pumps in bronze from Bolsena in Etruria (Nos. =338=, =339=; figs. 127, 128) are of special interest. These are constructed on a principle invented by Ktesibios of Alexandria, who probably lived in the third century B.C. They were worked by alternating plungers, raised and lowered by a rocking-beam. The first illustration (fig. 127) shows the less advanced but more complete pump in section, and explains the method, of working. The bottoms of the cylinders (A) were connected by pipes with the reservoir, and are furnished with flap-valves (B), opening upwards. When the plunger (C) was raised, a vacuum was created, and the water lifted the valve and rushed in. When the plunger was raised to its highest point the valve fell again and retained the water; when the plunger descended it forced the water from the cylinder into the central discharge pipe through another flap-valve (D) at the end of the horizontal pipe. BD in the figure shows the structure of the flap-valves, which the Greeks called [Greek: assaria] ("pennies") from their likeness to coins. F is a complete plunger of the same type as those used in the pump illustrated, but not belonging to it. Only two-thirds of the second pump (No. =339=) survive, but the missing part (marked off in the diagram by a dotted line) is supplied in the section (fig. 128). In this example the more advanced spindle valve takes the place of the flap valves, and the two valves side by side open into a central domed chamber, in place of the simple central cylinder of No. =338=. [Illustration: FIG. 128.--SECTION OF SECOND ROMAN BRONZE PUMP, FROM BOLSENA (NO. 339).]