Tamsen was an expert in the stamps of Transvaal, about which he researched and wrote, and he was one of the founders in 1894 of the Johannesburg Philatelic Society.
Tamsen was an expert in the stamps of Transvaal. He researched. He wrote about the stamps of Transvaal. He was one of the founders in 1894 of the Johannesburg Philatelic Society.