Specialist Report

Date 1980

Event ID 928743

Category Documentary Reference

Type Specialist Report

Permalink http://canmore.org.uk/event/928743

The 119 lead ingots found on the seabed off Stoura Stack are significant both in the context of the wreck and within the wider setting of 17th century lead production. The ingots were found packed in the bottom of a gully or piled on the seabed, and were raised beneath empty tar barrels before being individually recorded. These ingots need not represent the totality of the lead carried on the vessel. A large area of metal detector contacts to the NW of the stack may indicate a further deposit, while some lead was possibly removed in early salvage operations.

The ingots consistently weigh just over 140kg, are boat-shaped (presumably for easy slinging) and are in some cases so similar that they were evidently cast in the same mould or at least from the same pattern. They bear varied stamps, and two (nos. 53 and 69) bear more elaborate decoration than the rest. Several display cooling-striations along the sides and many have concave upper surfaces, again through cooling. Some have bumps on the underside, reflecting damage to a sand mould on initial pouring, while deposition and settling on the seabed occasional caused dents or slight buckling; surface corrosion has produced a white or grey patina in some cases. Several examples are heavily encrusted with worm casts and other marine deposits.

Cluster analysis has identified nine groups, 28 ingots being misplaced or undefined, and indicated a close relationship between the stamps and variations in form. Analysis of the pattern of deposition indicates no obvious pattern of classes across the site, an impression which is generally confirmed by statistical evaluation. Exceptionally, the ingots found in the upper part of the main gully are of exceptional form and weight; these may represent 'makeweights' added to the upper layers.

The origin of the lead is unknown, although England (notably Derbyshire) or central Europe may be suggested. In general, the ingots conform to the pig-like shape typical of English examples, and an English origin appears most probable. The stamps are assumed to represent control-marks applied by producers, middlemen or the VOC; some may also represent dates.

(For details of individual ingots, see tab. 1. For dendrogram of cluster analysis and plan of locations of discovery, see figs. 13 and 14 respectively).

Information from RCAHMS (RJCM) Undated

Source: R Price, K Muckelroy and L Willies 1980.