This is a reply to your first response - Thomas was a teenager when the canal went through Lower Heyford. Is this speculation on your part or was a canal being dug through Lower Heyford?
Yes there was a canal being dug.
Hope I am not stepping on jaywit's toes, the Oxford canal finally reached Oxford in 1790, where it joined the navigable river Thames.
Pure speculation but I wonder if his parents were already Thames boatmen, clutching at straws there is a birth at the right time in Kintbury, which is on the navigable Thames tributary the river Kennet,
Mike
