Page 40 - Art In The Age Of Exploration (Great Section on Chinese Art Ming Dynasty)

where, based on that coordinate, the solar decli- India] that it was Abraham Zacuto himself. to combine rules to be used by mariners with
nation was read. But this table of Zacuto re- The most famous and most widely dissemin- the Portuguese version of Sacrobosco's treatise
ferred only to entire degrees of ''places/' which ated quadrennial tables of solar declinations Da Esfera, to shed some light on elementary
he subjected to mathematical operations that, cover the period 1517 to 1520. These were cosmography. At least two known publications
given the ignorance of adequate logarithms at published (with printing errors) in the so-called did just this, the second constituting an im-
that time, were complex and certainly beyond Guia Nautico de Evora (Nautical Guide of provement on the first. These pamphlets, each
the understanding of a pilot. Evora), and later copied many times. It is known from a unique copy, are today called
Therefore, mathematicians already able to known that Caspar Nicolas calculated them, Guia Nautico de Munique (Nautical Guide of
undertake such calculations were commissioned because Valentim Fernandes so states in his Munich) (ist edition, copy in the Bayerische
to provide tables with solar declinations for the 1518 edition of the Repertorio dos Tempos Staatsbibliothek, Munich) and the Guia Nautico
use of pilots at sea. At first they were prepared (Repertory of the Times), which contains a de Evora (znd edition, Biblioteca Publica e
roughly and for only one year at a time (only transcription of the tables. Caspar Nicolas was Arquivo Distrital de Evora); some believe that
one of these tables is known). Later they were the author of the first treatise on arithmetic the Munich edition is in fact a reprint. It is
prepared for four-year periods, that is, for com- published in Portugal, in 1519. certainly surprising that this pamphlet, which
plete revolutions of the sun, and with greater does not bear a date but can be dated to 1509,
accuracy. Such quadrennial tables of solar decli- * X * * * presents only a one-year solar table, when
nations existed in the fifteenth century, of This historical summary of the development of better quadrennial tables with the declinations
which some remains are found in the Livro de the art of navigation during the second half of the sun had already been calculated. The
Marinharia (Book of Seamanship) by Andre of the fifteenth century leads us well into the material in these Portuguese pamphlets was
Pires, which includes a series of tables covering realm of modern navigation. This progress was translated or adapted into Spanish, French,
the period 1497 to 1500. These must have been widely recognized as such throughout Europe. Italian, English, Flemish, and German. The
used by Vasco da Gama's pilots. It is not known Indeed, at least since the beginning of the knowledge they contained was recognized as
who calculated these tables, but Caspar Correia sixteenth century, it was recognized within new and was widely disseminated.
suggests in the Lendas da India (Legends of nautical circles in Lisbon that it would be useful

EUROPE AND THE MEDITERRANEAN WORLD 39