Hero of Alexandria

The construction of a self-opening door is as follows: beneath the threshold, place a hollow sphere, and let a pipe pass from the sphere to the door.

To make a vessel which shall pour out water when it is full, and wine when it is empty, construct two compartments within the vessel, one for water and one for wine, and connect them by means of a siphon.

The principle of the fire engine is that water, forced through a nozzle, can be used to extinguish fires.

To construct a device which shall cause a bird to drink when water is poured into a basin, place a hollow bronze bird in the basin, and connect it to a pipe which is immersed in the water.

The construction of a self-lighting lamp is as follows: within the lamp, place a float, and connect it to a flint and steel by means of a lever.

To make a fountain which shall flow with oil on one day, and with vinegar on another, construct two vessels, one for oil and one for vinegar, and connect them by means of pipes and valves.

The principle of the surveying instrument is that a series of sights and angles can be used to measure distances and elevations.

To construct a device which shall cause a statue to speak when fire is kindled on an altar, place a vessel of water beneath the altar, and connect it to the statue's mouth by means of pipes.

The construction of a self-closing door is as follows: beneath the threshold, place a hollow sphere, and let a pipe pass from the sphere to the door.

To make a vessel which shall pour out wine when it is empty, and water when it is full, construct two compartments within the vessel, one for wine and one for water, and connect them by means of a siphon.

The principle of the automatic theater is that a series of ropes and pulleys, connected to figures, can be used to create a dramatic performance.

To construct a device which shall cause a bird to fly when water is poured into a basin, place a hollow bronze bird in the basin, and connect it to a pipe which is immersed in the water.

The construction of a self-winding clock is as follows: within the clock, place a float, and connect it to the mechanism by means of a lever.

To make a fountain which shall flow with beer on one day, and with mead on another, construct two vessels, one for beer and one for mead, and connect them by means of pipes and valves.

The principle of the screw press is that a screw, turning within a nut, can be used to apply pressure.

To construct a device which shall cause a statue to sing when fire is kindled on an altar, place a vessel of water beneath the altar, and connect it to the statue's mouth by means of pipes.

The construction of a self-filling lamp is as follows: within the lamp, place a smaller lamp, and connect the two by means of a siphon.

To make a vessel which shall pour out water when it is empty, and wine when it is full, construct two compartments within the vessel, one for water and one for wine, and connect them by means of a siphon.

The principle of the geared mechanism is that a series of gears, meshing with each other, can be used to transmit motion and power.

To construct a device which shall cause a bird to dance when water is poured into a basin, place a hollow bronze bird in the basin, and connect it to a pipe which is immersed in the water.