William YARE (1871-?)

Today I am working on William YARE, born in 1871. He is my 4th cousin, twice removed, our common ancestor being Joseph YARE (c1755-1829).

William appears in the 1881 and 1891 censuses, but not in 1901 or 1911. There is no obvious death for him, and without another census entry it is difficult to propose a marriage.

But there is a W. YARE listed as a Blacksmith on the Imperial Military Railway in South Africa during the Boer War. Is this him, and how do I discover more?