Measurements are key to monuments | Letter

Rose Harvie looks into the groundbreaking work of Professor Alexander Thom

Your fascinating report states that the Durrington Shafts discovery offers the first evidence that the early inhabitants of Britain ... had developed a way to count" (Vast neolithic circle of deep shafts found near Stonehenge, 22 June).

Evidence of this may well be found and accepted, but as early as the 1950s, Professor Alexander Thom claimed to have evidence that neolithic communities based the measurements of their monuments on a fixed unit of length. He called this the megalithic yard (approximately 2.7ft) and claimed that a multiple of these, the megalithic rod (6.8ft), was also used.