On page 170 of the original article, the photos of Don Robins and Robert Hale are superimposed on a photo of Moel Tŷ Uchaf stone circle, with the following caption:
Dan [sic] Robins takes Geiger readings at Moel ty Uchaf (above left). Such readings are often anomalous. Infrared photography (top, Moel ty Uchaf) and measurement of quartz periodicity (by Rodney Hale, at Rollright) also sometimes give odd results