|This reference from Rydale and North Yorkshire Antiquities by George Frank published in 1888 echoes Paulus's account from E. Boggs regarding the fate of the fourth stone.
A fourth 'Arrow' originally stood near the central one ...The upper half of this stone is in the grounds of Alborough Manor, the lower portion having being used at Boroughbridge, in building the foundations of 'Peggy Bridge'.
The Boroughbridge Town Council website
The upper section of the fourth stone is claimed to stand in the grounds of Aldborough Manor and the lower part is believed to form part of the bridge which crosses the River Tutt in St. Helena just a few hundred yards away on the route into the town centre. Large pieces of the same millstone grit have turned up in the garden of a house bordering the field in which the enclosure containing the largest arrow stands.
Two large boulders of the same material as the stones have been found in the garden of a house only a hundred yards or so from the line of the stones and may possibly be part of the fourth stone which was broken up by treasure hunters..
Posted by fitzcoraldo
13th November 2007ce
Edited 13th November 2007ce