

There is no record of William Dryden Hall as the son of Thomas Williamson Hall. Their 3rd son is recorded as William Henry Hall by the Hall family biographers.
Letters to Grace : Writing Home from Colonial New Zealand. Edited by Jean Garner & Kate Foster, 2011, Canterbury University Press, Christchurch, New Zealand
Hall family have confirmed there was no baby called William Dryden Hall. They think someone must have got confused with William Dryden, father of Rose Ann Hall and Agnes Emma Hall. Thomas Williamson Hall names his sons in his will. One is William Henry Hall and I think he was a solicitor from the wording in the will.