Mark,
The two 1901 entries are:
Martin Arthur, ON, TORONTO (East/Est) (City/Cité), Ward/Quartier No. 1, a-4, page 3, line 35; and
Martin Arthur J., BC, YALE & CARIBOO, Kootenay (East/Est) - (South Riding/Division Sud), e-4, page 23, line 38.
the 1891 entry is
Arthur Martin, page 11, line 9Although the census indicates that they are both born on 10 Oct 1864, I do not beleive that they are the same individual when looking at the other columns:
Arthur enumerated in Ontario, the census entry indicates that he was born in Ontario urban, of Irish origin, religion: Presb, Occupation: Teamster, working in a factory for 12 mth for an annual salary of $400; while
Arthur J. enumerated in B.C., the census entry indicates that he was born in Quebec urban, of French origin, (no religion indicated), Occupation : RY Conductor, working for 12 mth for an annual salary of $900.
the 1897 census entry match the 1901 entry in B.C. except for the name of his wife. Since his wife in 1897 is Euginie his wife in 1901 is Josephine, did Euginie died between 1897 and 1901?
I would disregard the Arthur Martin enumerated in ON in 1901 as a coincidence that they have the same birth date especially based on the occupation difference.
Cheers