A total of 127 fragments of glass were excavated from the “Tortugas” shipwreck, including square-sectioned case bottles. The bases of these bottles are all medium olive green in color and contain air bubbles. Glass rims and neck sherds were recovered still attached to 14 lead screw collars and caps that originally sealed some of the “Tortugas” ship’s bottle mouths. Data suggests a minimum presence of 16 square-sectioned bottles on the ship.
The square-sectioned bases derive from what would later become called case bottles that were common throughout Europe and the Americas. The term comes from the fact that square-sided bottles were particularly developed for packing in wooden cases with compartments (cellarets) for oceanic voyages. Such bottles primarily contained spirits which were essential in the 17th century when natural water supplies were considered infectious and alcohol was taken for medicinal purposes. However, as with most bottles of the era, after being emptied the bottles were often reused for different products, which may have been the case on the return voyage of the “Tortugas” ship.
The “Tortugas” bases are part of a square-molded bottle type that was seemingly first produced in Germany in the last quarter of the 16th century. Similar bottles dating from 1570-1600 were also manufactured in the glasshouses of Bohemia and Belgium. The typically green glass form was subsequently introduced into the Rotterdam area of the Netherlands, which began manufacture on a large scale in the 17th century as the country evolved into Europe’s major shipping center.
The two-piece permanent lead collars and caps that originally closed the bottles’ mouths feature everted sides and a horizontal shoulder surmounted by a short vertical mouth. Each collar, 1.4-1.9cm high, is subdivided into two seamless elements: at top a narrow screw thread (W. 1.5-1.9cm, Th. 0.2cm) consisting of three convex external edges between two inner recessed threads for receipt of a lead cap, and below the main section (max W. 2.1-3.3cm, bottom W. 1.9-2.9cm, Th. 0.2-0.4cm) that originally covered and protected the glass bottle neck and rim. The two zones are separated by a horizontal ledge, furrowed on the lower edge. The bottom edge of the inner diameter, reflecting the bottle’s neck diameter, ranges from 1.2-1.7cm. The collar was a permanent component cast over the bottle.
Especially significant for the case of the “Tortugas” shipwreck are the identical glass bottle bases and lead bottle caps associated with two of other vessels of the 1622 Tierra Firme fleet. As in the case of the “Tortugas” wreck, square-sectioned bottles are the most common glasswares aboard the Atocha. The Margarita wreck site also yielded a number of bottle closures comparable to the “Tortugas” examples, evidence that the same products were aboard this ship as well.
Similar glasswares have been excavated from other Spanish shipwrecks. An intact square-sectioned green bottle was stocked on the Spanish galleon Nuestra Señora de la Concepción, sunk off Hispaniola in 1641. Pewter caps from square-sectioned bottles were recovered from the San Martin, the Almiranta of the Honduras fleet en route from Havana to Spain in 1618, and were still in use a century later on the 1715 fleet wrecked off Florida. On the basis of this evidence, is it reasonable to propose that one line of lead-capped square bottles conceivably may have been manufactured in Spain, mirroring in glass the overwhelming dominance of Seville wares amongst the "Tortugas"ceramics.