Page 223 - Vol_2_Archaeology of Manila Galleon Seaport Trade

12 Clues to Internationalism in the Manila Galleon Wreck … 195

Fig. 12.6 A sheet of lead with iron tack heads is characteristic of Spanish and Portuguese
long-range trading ships

their long-range trading ships to keep the teredo navalis, or shipworm, out of the
timbers and to keep seaweed and barnacles from attaching themselves to the hull
and slowing it down. 4
Spanish-colonial coins are marked with the sources of the silver that drove the
trans-Paci!c trade and soon became the world’s money system. The ones we !nd
are heavily encrusted with sand and patination products (Fig. 12.7). They range
from one one-real piece, through six two-reales and two four-reales, to one
eight-reales, also known as a Peso, Piece of Eight, Taler, and eventually Dollar. The
Piece of Eight weighs approximately one ounce, or 28 g. Our !nds can be identi!ed
as belonging to the second coinage design of Spanish King Philip II, which went
into production in Mexico City in 1572 and in Potosi, Upper Peru, in 1574 5
(Fig. 12.8). They are all from the new design, which can be explained by
Gresham’s Law, which says that people keep “good” coins and spend “bad” coins.
In this case, crewmen kept the most modern coins for use when they returned to
Mexico from the Philippines, but they had spent the older coins and silver bars to
buy Asian goods in the Philippines. So far, we can read four of the ten coins we
have found. Others await conservation. One four-real and two two-reales are from
the Mexico City mint with the of!cial’s mark “O.” The piece of eight is from

4
The lead sheathing has not yet been analyzed and published.
5
The key coin catalog for identifying Spanish-colonial coins is Calbeto de Grau (1970). Much
detailed information about the New World mines, silver production, the Mexico City and Potosi
mints, minting techniques, and the coins is in Craig (2000).