Roman camps UK - is there a database or list?

[Nathan Ross]

May I ask what you would see the legionnary using his nine litres for?

Well, they'd need something to wash the shampoo out of their hair and moisten their toothpaste... mile:

Actually, what Roth writes is, "Each and every member of the army required a minimum of two liters of water per man per day, in addition to the two liters a day consumed through food and absorbed by breathing air" (p.119). You've missed the significance of 'in addition' which brings Roth's total to at least 4litres/man/day. Figures on inhaled water-vapour... brings Roth's figures to 4.5litres/man/day.

The 'in addition' is a bit obscure - I read it as meaning that the additional two litres are provided by water in food and air, not that extra litres were required! So inhaling air would provide 0.5 litres, as you say, and eating food 1.5 litres, meaning that only minimum 2 litres are needed for actual drinking, cooking etc. But I haven't checked on Roth's sources, and I'm prepared to bow to your (apparently) more considered approach.