The mine shares out its flow through ten conduits and there are only six meters. The parishes suspect that one of them gets less than its deed allows.
At every distribution tank, what goes in is what comes out. That alone fills in the four unmetered conduits.
The water of the royal mine is shared out through tanks, and from each tank conduits run on to other tanks or to the fountains of the parishes. Not every stretch has a meter, and none is needed: inside a tank no water is lost and none is gained, so whatever is not measured is worked out.
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