英雄港博物馆（Museu de Angra do Heroísmo）的16世纪铸铜炮

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MAH 2

This Portuguese reinforced demi-culverin9 (fig. 16) bears the Arms of Portugal above the armillary sphere on the third reinforce (fig. 17), and a three-leaf pattern around its sunken touchhole, which was likely a symbol of the founder. It is reinforced with simple astragal bands, and has a set of four lifting rings on the reinforces, and one lifting ring at the cascabel. Unlike any of the other guns in this collection, on the muzzle side of the trunnions, there is a place on the gun where the diameter changes abruptly; what I call a step-down band (fig. 18).

Several flaws are apparent upon inspection of MAH 2. There are depressions in the muzzle, evidence of the use of insufficient metal in casting. Other flaws include cracks under the first set of reinforcement rings, and cracks and holes behind the muzzle set of lifting loops. The fact that these cracks exist under the rings makes it likely that they occurred when the model was being made. The plain model (without any embellishments or reinforces) may have been improperly dried, allowing the cracks to form. The founder may have not seen them as he applied the extra clay and used the strickle board to produce the reinforcement rings. Or, it may be that he chose this location to apply the rings because of the cracks in the clay. The rings were cast with the gun, and were not later additions designed to strengthen a weak spot on the tube.

Overheating brought about by an excessively rapid rate of fire probably caused another problem with this gun. Its muzzle droops slightly, starting 49 centimeters (1.6ft) from the face of the muzzle. As was discussed earlier, when bronze generates too much heat, it anneals. As the muzzle is the least supported and fortified part of the gun,

Fig. 16. The Portuguese reinforced demiculverin

MAH 2.

Fig. 17. The Arms of Portugal and armillary

sphere on MAH 2.

Fig. 18. The step-down reinforcement ring on MAH 2.

it is here that gravity takes affect and draws the metal down, as was the case on MAH 2.

In the Museu Militar in Lisbon, the gun labeled R-16, dated to the first half of the 16th century, bears a resemblance to MAH 2. The types of reinforcement rings, simple astragals as well as a step-down, are the same, and these are a type that I rarely saw. The base ring and muzzle also bear a striking resemblance, including the same depressions in the muzzle face. The arms of Portugal (fig. 19) and the armillary sphere on this gun are all but identical to those on MAH 2. In addition, there is a similar 3-leaf pattern found on one side of the reinforcement rings, as well as along the base ring, that is similar to that around the touchhole of MAH 2.

The step-down reinforcement band is a feature shared by a Portuguese bastard double culverin (C-4), a Portuguese eagle (C-5/A), and a Portuguese stone-thrower (C-6) at the Museu Militar, all dating to the first half of the 16th century. The first gun also bears a three-leaf pattern around its sunken touchhole, similar to that of MAH 2. The last gun (C-6) has the same simple astragal reinforcement rings as MAH 2, as does a Portuguese camelo (C-7), which, again, dates to the first half of the 16th century. C-7 also has the remains of a lifting ring at the breech, similar to MAH 2.

Based on comparative evidence, MAH 2 appears to date to the first half of the16th century, which agrees with the Museu de Angra booklet that dates it to the reign of Manuel I.10 Important characteristics to note of the guns from the reign of Manuel are the relatively flat cascabels, with or without rings, as well as the presence of an armillary sphere.11