Evidence for literacy on the “Tortugas” ship is present in the form of an onyx set of inkwell, shaker and several bronze styli. This discovery is not surprising given the detailed bookkeeping practiced by Spain in its long-distance maritime trade. The inkwell located is crafted of onyx and consists of a square cube featuring a central ink reservoir and four holes on the upper edges to hold pens. A circular lid enabled the well to be closed when not in use. The onyx shaker also has a central reservoir but in this example is pierced with 12 holes designed to allow powder to be dispersed over parchment and dry ink.
This style of inkwell, seemingly in bronze and with geometrically decorated sides, is depicted in Francisco de Zurbaran’s Visit of San Bruno to Urbano II painted in 1655. An exact bronze parallel was also excavated from the Spanish ship the San Diego. A hardy stone version impervious to humid, salty environments was a sound choice for shipboard use.