1 The Birth of Science - MSRI

4.5 Naval Architecture. The Pharos 101
unexpected race toward ever larger ships. 75 It seems that the cataphracts
used by Antigonus II of Macedonia against Ptolemy II Philadelphus in the
naval battle near Cos (ca. 260 B.C.) were as big as fifteen quadriremes —
and the race was not even on the final stretch.
In classical times the main type of vessel had been the trireme. Its name,
in both Greek and Latin, is composed of the words for “three” and “oar”,
but the exact meaning of the term has been a subject of debate since late
Antiquity. Some maintained that there were three rowers per oar, but the
prevailing view today is that there were three stacked oar banks. In Hellenistic
times there appear multiremes with rapidly increasing numbers,
culminating with the forty-reme built by Ptolemy IV Philopator; such large
numbers clearly require a different interpretation. The commonest opinion
today is that they indicate the total number of rowers manning all oars
comprising a vertical column. All we can be sure of is that these new terms
indicate ships much bigger than their predecessors, and this sudden, drastic
increase indicates qualitative changes in shipbuilding technology. One
of the motivations for increasing the size of men of war, even at the expense
of maneuverability, was probably the diffusion of artillery: growing
use was made of ships as floating platforms that could accommodate catapults
and other war engines.
Merchantmen also got bigger. Hiero II of Syracuse had a cargo ship
built, the Syracusia, which Moschio described in a book of which generous page 140
portions are quoted by Athenaeus. 76 Thus we know that the ship, whose
construction had required as much wood as sixty quadriremes, had on
board, among other things, a gymnasium, a library, hanging gardens and
twenty horse-stalls. Just before the Syracusia, Athenaeus discusses other
ships of similar dimensions, built in Alexandria by the Ptolemies.
No remains of these enormous ships have been found, but undersea
archeology has amassed a consistent record on smaller ships. One of the
first important finds took place in 1954, near the islet of Grand Congloué,
offshore from Marseilles. 77 It consisted of the remnants of a Hellenistic
ship of the mid-second century B.C., about 23 meters long and lead-plated.
We now know that lead plating, used to protect the hull from barnacles,
was common in ships of the time; yet as late as the seventeenth century
British and Dutch ships had no such defense.
The theoretical calculation of waterlines, which as we saw occupied
Archimedes in his On floating bodies, probably gained in importance from
shipbuilding innovations in terms of materials and size. One couldn’t just
75 See [Casson: AM], [Casson: SS], [Morrison].
76 Athenaeus, Deipnosophistae, V, 206–209.
77 [Benoit].
Revision: 1.14 Date: 2002/10/24 04:25:47