We have arrived at downtown Stageira. What today is a large, flattish open space in the valley between the city's two hills, was once its agora, the market and place of public assembly (see next page).

This large stone water tank, at the foot of the South Hill, opposite the agora, is in an area thought to have been occupied by public buildings. The tank was once quite a grand structure, with well-made stonework. Its interior was covered with lead sheeting, which made it water-tight but also presented a health hazard to users. Lead water tanks and pipes were widespread from antiquity until the end of the last century, and in many places are still in use. These days we know that lead poisoning is detrimental to physical and mental health [1], and this has led to much speculation over what effect this has had on history. Roman emperors, for example, enjoyed wonderful water supplies, but many of them were as mad as hatters.

Water was not only crucial to the survival of a city - its military and commercial viability - it also had a vital social aspect. People met at wells and fountains to chat and gossip while having a drink or gathering water for their shops and houses. Such structures were a source of civic pride, and often had historical or religious significance for the inhabitants. Public works projects were sometimes undertaken with funds from commerical successes or military victories. Often rich and powerful idividuals or families would donate waterworks to a city as an act of public benefaction.

To ensure the purity of water supplies, some cities made laws concerning the use of public fountains and wells, which were displayed on stone inscriptions. Penalties for breaking these laws could be severe.

Aristotle had this to say about the importance of water supplies in his ideal city:

"It should next be contrived... that there may be plenty of water, and rivers near at hand. But if those cannot be found, very large cisterns must be prepared to save rain-water, so that there may be no want of it in case they [the citizens] should be driven into the town in time of war.

And as great care should be taken of the health of the inhabitants, the first thing to be attended to is, that the city should have a good situation and a good position; the second is, that they may have good water to drink; and this not be negligently taken care of. For what we chiefly and most frequently use for the support of the body must principally influence the health of it; and this influence is what the air and water naturally have: for which reason in all wise governments the waters ought to be appropriated to different purposes, and if they are not equally good, and if there is not a plenty of necessary water, that which is to drink should be separated from that which is for other uses."

1. Lead poisoning from ancient plumbing

The health hazards of using lead were known from at least as early as the early Roman Imperial period, and were mentioned by the Roman architect and engineer Vitruvius (circa 80–70 - after circa 15 BC).

"Clay pipes for conducting water have the following advantages. In the first place, in construction: if anything happens to them, anybody can repair the damage. Secondly, water from clay pipes is much more wholesome than that which is conducted through lead pipes, because lead is found to be harmful for the reason that white lead is derived from it, and this is said to be hurtful to the human system. Hence, if what is produced from it is harmful, no doubt the thing itself is not wholesome.

This we can exemplify from plumbers, since in them the natural colour of the body is replaced by a deep pallor. For when lead is smelted in casting, the fumes from it settle upon their members, and day after day burn out and take away all the virtues of the blood from their limbs. Hence, water ought by no means to be conducted in lead pipes, if we want to have it wholesome. That the taste is better when it comes from clay pipes may be proved by everyday life, for though our tables are loaded with silver vessels, yet everybody uses earthenware for the sake of purity of taste."

Vitruvius, De Architectura (On Architecture), Book VIII, chapter VI "Aqueducts, wells and cisterns", sections 10-11.

Vitruvius also mentions the danger of water supplies near sources of certain metals, which is of direct relevance to the mining areas around Stageira:

"Copious springs are found where there are mines of gold, silver, iron, copper, lead, and the like, but they are very harmful. For they contain, like hot springs, sulphur, alum, asphalt, ... and when it passes into the body in the form of drink, and spreading through the veins reaches the sinews and joints, it expands and hardens them. Hence the sinews, swelling with this expansion, are contracted in length and so give men the cramp or the gout, for the reason that their veins are saturated with very hard, dense, and cold substances."

Vitruvius on the eureka moment

And while we're on the subjects of Vitruvius, water and gold, we could not resist mentioning that it was Vitruvius who told us about Archimedes and how he made one of his greatest discoveries while having a bath.

"In the case of Archimedes, although he made many wonderful discoveries of diverse kinds, yet of them all, the following, which I shall relate, seems to have been the result of a boundless ingenuity. Hiero, after gaining the royal power in Syracuse, resolved, as a consequence of his successful exploits, to place in a certain temple a golden crown which he had vowed to the immortal gods. He contracted for its making at a fixed price, and weighed out a precise amount of gold to the contractor. At the appointed time the latter delivered to the king's satisfaction an exquisitely finished piece of handiwork, and it appeared that in weight the crown corresponded precisely to what the gold had weighed.

But afterwards a charge was made that gold had been abstracted and an equivalent weight of silver had been added in the manufacture of the crown. Hiero, thinking it an outrage that he had been tricked, and yet not knowing how to detect the theft, requested Archimedes to consider the matter. The latter, while the case was still on his mind, happened to go to the bath, and on getting into a tub observed that the more his body sank into it the more water ran out over the tub. As this pointed out the way to explain the case in question, without a moment's delay, and transported with joy, he jumped out of the tub and rushed home naked, crying with a loud voice that he had found what he was seeking; for as he ran he shouted repeatedly in Greek, 'Ευρηκα, ευρηκα' [I've found it]."

2. Aristotle on the water supply in the ideal city

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