On Architecture

3. Pistons smoothly turned, rubbed with oil, and inserted from above into the cylinders, work with their rods and levers upon the air and water in the cylinders, and, as the valves stop up the openings, force and drive the water, by repeated pressure and expansion, through the vents of the pipes into the vessel, from which the cowl receives the inflated currents, and sends them up through the pipe at the top; and so water can be supplied for a fountain from a reservoir at a lower level.

4. This, however, is not the only apparatus which Ctesibius is said to have thought out, but many more of various kinds are shown by him to produce effects, borrowed from nature, by means of water pressure and compression of the air; as, for example, blackbirds singing by means of waterworks, and “angobatae,” and figures that drink and move, and other things that are found to be pleasing to the eye and the ear.

5. Of these I have selected what I considered most useful and necessary, and have thought it best to speak in the preceding book about timepieces, and in this about the methods of raising water. The rest, which are not subservient to our needs, but to pleasure and amusement, may be found in the commentaries of Ctesibius himself by any who are interested in such refinements.

1. WITH regard to water organs, however, I shall not fail with all possible brevity and precision to touch upon their principles, and to give a sufficient description of them. A wooden base is constructed, and on it is set an altar-shaped box made of bronze. Uprights, fastened together like ladders, are set up on the base, to the right and to the left (of the altar). They hold the bronze pump-cylinders, the moveable bottoms of which, carefully turned on a lathe, have iron elbows fastened to their centres and jointed to levers, and are wrapped in fleeces of wool. In the tops of the cylinders are openings, each about three digits in diameter. Close to these openings are bronze dolphins, mounted on joints and holding chains in their mouths, from which hang cymbal-shaped valves, let down under the openings in the cylinders.

2. Inside the altar, which holds the water, is a regulator shaped like an inverted funnel, under which there are cubes, each about three digits high, keeping a free space below between the lips of the regulator and the bottom of the altar. Tightly fixed on the neck of the regulator is the windchest, which supports the principle part of the contrivance, called in Greek the kanw\n mousiko/s. Running longitudinally, there are four channels in it if it is a tetrachord; six, if it is a hexachord; eight, if it is an octachord.

3. Each of the channels has a cock in it, furnished with an iron handle. These handles, when turned, open ventholes from the windchest into the channels. From the channels to the canon there are vertical openings corresponding to ventholes in a board above, which board is termed pi/nac in Greek. Between this board and the canon are inserted sliders, pierced with holes to correspond, and rubbed with oil so that they can be easily moved and slid back into place again. They close the above-mentioned openings, and are called the plinths. Their going and coming now closes and now opens the holes.

4. These sliders have iron jacks fixed to them, and connected with the keys, and the keys, when touched, make the sliders move regularly. To the upper surface of the openings in the board, where the wind finds egress from the channels, rings are soldered, and into them the reeds of all the organ pipes are inserted. From the cylinders there are connecting pipes attached to the neck of the regulator, and directed towards the ventholes in the windchest. In the pipes are valves, turned on a lathe, and set (where the pipes are connected with the cylinders). When the windchest has received the air, these valves will stop up the openings, and prevent the wind from coming back again.