I have just discovered that doing a search in familysearch.org that there were 3 children born to a John Sturgeon (Brother of Thomas) and Jane Clark.
They are:
Mary b. 03/03/1869, Down, Ireland
Elizabeth b. 13/11/1866, Waringstown, Down, Ireland
Samuel b. 21/08/1873, Lurgan No.1, Armagh.
I am struck with the Lurgan link given the previous posts.
Also Thomas lived next door to a Samuel Sturgeon (b. @1851 Ireland) in Glasgow in 1891. Although they are different ages. I am note the common name.
Regards,
Bullywee