The Athenians named four officers to keep watch and ward over the water.[XXV-10] The other Greek towns followed the example. These officers had to keep the fountains in order and clean the reservoirs,[XXV-11] so that the water might be preserved pure and limpid. The Romans at first contented themselves with water from the Tiber. King Ancus Martius[XXV-12] was the first[XXV-13] to build aqueducts, destined to convey the water of the fountain of Piconia from Tibur to Rome, a distance of about thirty-three thousand paces. Some have honoured the censor, Appius Claudius, for this magnificent undertaking,[XXV-14] to whom is certainly due the celebrated Appian Way.[XXV-15] These gigantic works greatly multiplied in time. Under the reign of Nero, Rome had nine principal aqueducts[XXV-16] constructed, the pipes of which were of bricks, baked tiles, stone, lead, or wood.[XXV-17] According to the calculation of Vigenerus,[XXV-18] 500,000 hogsheads of water were conveyed into Rome every twenty-four hours, by 10,850 small channels, the internal circumference of which was one inch. The water was received in large closed basins, above which were raised splendid monuments. These basins--or _châteaux d’eau_--_castella Aquarum_--supplied other subterraneous conduits connected with the various quarters of the town,[XXV-19] which conveyed water to small reservoirs--_fontes_--furnished with taps, for the exclusive use of certain streets.[XXV-20] The water which was not drinkable ran out by means of large pipes into extensive inclosures, where it served to water cattle. At these places the people washed their linen, and here, too, they had a ready resource in case of fire.[XXV-21] Augustus created water commissaries, who took care that all water coming into Rome by the aqueducts was fairly distributed in every public place, and to those of the inhabitants who had obtained the privilege of having it enter their houses.[XXV-22] But the “ingenious thirst”[XXV-23] of the conquerors of the world could not content itself with a delicious water which nature furnished free of expense. Was it not too much for human endurance, that not only the air and the sun could not be offered to the highest bidder,[XXV-24] but that the same spring was to quench the thirst of obscure plebeians on equal terms with the rich patrician? Intemperance and luxury very soon contrived to find excellent means of remedying a state of things so intolerable. The custom of preserving snow in cellars, to obtain cool beverages, is very old. Aristotle pointed out the method of boiling water, and putting the vessel afterwards in snow, in order to obtain ice. Rome had recourse to this expedient, which was afterwards replaced with advantage, under Nero, by constructing ice houses for the use of opulent epicureans.[XXV-25]