of August, 1653, De Ruyter saved a great convoy by beating off Sir
George Ayscough's fleet of 38 sail, the largest of the Dutch admiral's
"33 sail of the line" carried but 30 guns and 150 men, and his own
flag-ship but 28 guns and 134 men. [Footnote: La Vie et les Actions
Memorables du Sr. Michel de Ruyter, a Amsterdam, Chez Henry et
Theodore Boom. MDCLXXVII. The work is by Barthelemy Pielat, a
surgeon in de Ruyter's fleet, and personally present during many
of his battles. It is written in French, but is in tone more
strongly anti-French than anti-English.] The Dutch book from which
this statement is taken speaks indifferently of frigates of 18, 40,
and 58 guns. Toward the end of the eighteenth century the terms had
crystallized. Frigate then meant a so-called single-decked ship;
it in reality possessed two decks, the main- or gun-deck, and the
upper one, which had no name at all, until our sailors christened
it spar-deck. The gun-deck possessed a complete battery, and the
spar-deck an interrupted one, mounting guns on the forecastle and
quarter-deck. At that time all "two-decked" or "three-decked" (in
reality three- and four-decked) ships were liners. But in 1812
this had changed somewhat; as the various nations built more and
more powerful vessels, the lower rates of the different divisions
were dropped. Thus the British ship _Cyane_, captured by the
_Constitution_, was in reality a small frigate, with a main-deck
battery of 22 guns, and 12 guns on the spar-deck; a few years
before she would have been called a 24-gun frigate, but she then
ranked merely as a 22-gun sloop. Similarly the 50- and 64-gun ships
that had fought in the line at the Doggerbank, Camperdown, and
even at Aboukir, were now no longer deemed fit for the purpose,
and the 74 was the lowest line-of-battle ship.

The _Constitution_, _President_, and _States_ must then be compared