Jim, Thank you so much for your reply - and for all the helpful suggestions.
I don't know which university he went to - neither do I have a lot of information about the army, apart from him being stationed in Balincollig, Cork when his son was young.
I know that Thomas Davidson had changed his name to Harrison by the time he married Alice May Griffiths in 1905 in Kent. They had one son William Thomas Harrison - my husbands father.
I will keep on with my search. Pamela