Balances and weights in Viking Age Sweden

Abstract

The Viking Age balances found in Sweden form a very homogenous group. Typically they have a sensitivity of 1 mm deflexion of the tip of the pointer for 0.2-0.4g overload at low loads. At loads around 2•50 or 2•100g, some 2 per cent will cause this deflexion. To obtain the optimum information from the many weights found, it is very important that only the very best weights are selected for your study. The small, 0.7-4.5 gram, cubo-octaedric weights found at Bandlunde and Paviken, Gotland, Birka, Upland and Hedeby, Germany, belong to the same system. It is probably based upon the weight dirhem = 2.83g although the canonical dirhem = 2.97gcannot be entirely excluded. The bronze clad iron weights were estimated indirectly by measuring and calculating their volume which was then converted into the weight. The Bandlunde weights belong to a system probably based upon the mitqal sanctioned by the chalif Abd al Malik in Bagdad AD 696. Their unit is c 4.25g.The Birka unit was only 4.0g.Some solid bronze weights derive from a unit=3.0g. It is an
impossible task to map all the different weighing systems used during the Medieval Age simply because administration in most areas was weak and did not own the technical facilities needed for a rigid control of weights and balances. For one type of trade, only, one may expect international weighing systems, the trade with precious metals. The high and persistent value of the goods made
the weighing meaningful. A piece of silver kept its weight even if it was carried to another market. In Scandinavia there have been found more than one hundred balances and several hundred weight pieces from the Viking age, mainly from the tenth and eleventh century. They are remarkably uniform and several authors have studied them and tried to attribute them to the various weight
system prevailing in Europe and the near East. The problem is, however that these systems are rather similar and that the exact nominal weight of the often severely corroded pieces is difficult and frequently impossible to establish. The accuracy to be expected in the weighing system has been another source of confusion, sometimes errors of ten per cent have been accepted as probable and
normal, in other cases the unit weight estimated is given with 4 or 5 decimals. The inexactness of the balances and of the weights contribute equally to the errors of the weighing and of the weighing system.