[Footnote 72: Even of fifteen and sixteen rows of oars, in
the navy of Demetrius Poliorcetes. These were for real use:
the forty rows of Ptolemy Philadelphus were applied to a
floating palace, whose tonnage, according to Dr. Arbuthnot,
(Tables of Ancient Coins, &c., p. 231 - 236,) is compared as
4 1/2 to 1 with an English 100 gun ship.]