processing copper ores (see under 'Function'). Some of the bold triangles and criss-cross incisions seem to be more Iron Age in character than Neolithic or Bronze Age. Function Suggested ceremonial use The possible use of the balls as oracles has been suggested. The way in which the ball came to rest could be interpreted as a message from the gods or an answer to a question. An alternative or supplementary use could have been as the 'right to speak' where discussions are controlled by the requirement for the speaker to hold the carved stone ball or if not, then keep their peace and listen to the views of others. The balls are of a size that fits comfortably in one hand. Suggested practical use Some of the balls have grooves or interspaces between the knobs into which leather could be tied so as to make a device such as a bolas. Their use as weapons was suggested by many researchers but in recent years this idea has fallen from favour. One suggestion saw the balls as movable poises on a primitive weighing machine, following the logic of the remarkable uniformity in size shown by a good number of these carefully made objects. However, it has been shown that their weights vary so considerably that mathematically they could not be considered part of a system of weight measurement. 'Sink stones' (fishing weights) found in Denmark and Ireland have some slight similarities, these artefacts being used in conjunction with fishing nets. Another possible use for the stones would be in the working of hides. Into the 20th century leatherworkers polished leather, parchment, and hides, by tying the skins to a frame using a ball at each corner of the hide then rubbing down material being worked with stones. The corners of the hides were wrapped around the balls which allowed the bindings to hold fast without slipping off. In more modern times, the balls were often made from scraps of the material being worked and the leather was cut away from the balls when the polishing was finished. This caused the balls to grow in size until the process had to be started over by replacing the oversized balls with scraps and beginning a new ball. Megalith construction aid A theory on the movement of megalithic stones for monuments has been put forward as a result of an observed correlation between standing