History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
For at Potidaea the number of heavy-armed that kept guard at two drachmas a day,
(for each man received one for himself and another for his servant,) was at first three thousand; and not fewer than these remained there to the end of the siege, besides one thousand six hundred with Phormio, who went away before it was concluded while all the ships, too, received the same pay. In this way then was their money heedlessly lavished at first; and such was the largest number of ships manned by them.