A set of highly decorated chalk cylinders, carved in Britain more than 4,000 years ago and known as the Folkton drums, could be ancient replicas of measuring devices used for laying out prehistoric monuments like Stonehenge, archaeologists say. The researchers from the University of Manchester and University College London said that a fixed number of turns of a string around the hand-size objects gives a standard measurement of 3.22 meters: a length that was used to lay out many Neolithic stone and timber circles.
     Three of the ornately carved chalk cylinders were found in 1889, near the village of Folkton, in Yorkshire (England). The smallest is 10.4 cm across, the next is 12.4 cm and the largest is 14.6 cm. They were found in the grave of a child, which is thought to date to the late Neolithic period or the early Bronze Age Beaker period in Britain.
     Due to the location of the find and the cylinders' unusual shape, archaeologists call the objects the Folkton drums. They were thought to be unique until a very similar carved chalk cylinder was found more than 100 years later, in the village of Lavant near England's south coast - it is called the Lavant drum.
     The researchers say the circumferences of both the Folkton and the Lavant drums are based on multiples of an ancient measure known to archaeologists as a 'long foot' of 32.2 cm. Previous research suggests this long foot was a standard length for measuring the concentric circles of standing stones and timber posts at Neolithic monuments like Stonehenge and Durrington Walls, an earth henge about 3.2 km northeast of Stonehenge.
     Archaeologists have determined that a string wound 10 times around the smallest of the Folkton drums would give a measure of exactly 10 long feet - a length used to lay out several ancient henge monuments. The same length of 10 long feet can be found by winding a string seven times around the largest of the Folkton drums, and eight times around the middle-size drum, the researchers said. Wrapping a string nine times around the Lavant drum would also equal 10 long feet.
     The lead author of the new study, University of Manchester archaeologist Anne Teather, said it wasn't clear why drums of different sizes were used to give the standard measure of 10 long feet. "There isn't one answer here, and probably there are several possible explanations," Teather said. "We have suggested that the different-size drums all give 10 long feet, but a different subdivision of that measure, so they may have been useful when fractions of the measure were required. Another explanation is that the drums were instructional teaching aids that would have been used to demonstrate some of the principles of mathematics and geometry," she said.
     Because the Folkton drums were found in the grave of a child, the researchers think the objects could have some sort of symbolic connection to childhood. "Does this mean that standard measures were somehow associated with children, or growth, or the human life-cycle including learning and the intergenerational transmission of knowledge?" study researcher Mike Parker Pearson, an archaeologist at University College London, wrote in a statement. "These items were almost certainly prestigious, although how, or to what extent they held social power, is unknown," he said.
     The archaeologists think the Folkton and Lavant drums are not the actual devices used for prehistoric monuments, but rather replicas. "Chalk is not the most suitable material for manufacturing measuring equipment, and it is thought that the drums may be replicas of original 'working' standards carved out of wood," wrote University of Manchester archaeologist Andrew Chamberlain, another author of the new paper. "However, wood is not preserved on most Neolithic archaeological sites and no wooden measuring devices have been found in prehistoric Britain," he said.
     The Folkton and Lavant drums suggest that the Neolithic monument builders of Stonehenge and other ancient henges possessed specialized geometric knowledge that may have been celebrated or taught to children in their culture.

Edited from LiveScience (28 January 2019)