From Chapter 24 of the Decline & Fall

Assyria yielded to the Persian satrap an *Artaba* of
silver each day. The well-known proportion of weights and
measures (see Bishop Hooper's elaborate Inquiry), the
specific gravity of water and silver, and the value of that
metal, will afford, after a short process, the annual
revenue which I have stated. Yet the Great King received no
more than l000 Euboic, or Tyrian, talents (252,000 l.) from
Assyria. The comparison of two passages in Herodotus (1. i.
c. 192, 1. iii. c. 89-96) reveals an important difference
between the *gross* and the * net* revenue of Persia; the sums
paid by the province, and the gold or silver deposited in
the royal treasure. The monarch might annually save three
millions six hundred thousand pounds, of the seventeen or
eighteen millions raised upon the people.