Libro general de las conversiones de plata y oro de diferentes leyes y pesos, organizadas de menor a mayor […]Juan de Belveder
The atmosphere of prosperity that existed thanks to the exploitation of the American mines contrasted with the martyrdom that the conversion of monetary units meant in the viceroyalties such as in Peru. For this reason, as Margarita Suárez points out, books appeared such as Juan de Belveder’s Libro general de las reduciones… (1597), which were manuals with conversion tables to facilitate the accounts. This work is the pioneer of a tradition that began in the 16th century: printing manuals in Lima with conversion tables to facilitate the accounts of merchants, royal officials and the population in general.
According to Salavert Fabiani, the contents of the volume can be divided into three sections. The first provides extensive information on the assay of precious metals, weights and fineness of gold and silver from the perspective of a specialist in arithmetic. The second presents a succession of tables of reductions in the value of different pieces of silver, changes in coins and the calculation of certain duties levied on goods and precious metals. In the third, the general rules used to compile the different tables are given in arithmetical form and forty-two problems are included, where reference is made to the rules of three and those of the false position.