The Collaborative International Dictionary of English v.0.48:

Topsman \Tops"man\, n.; pl. Topsmen.
   1. The chief drover of those who drive a herd of cattle. --P.
      Cyc.
      [1913 Webster]

   2. The uppermost sawyer in a saw pit; a topman. --Simmonds.
      [1913 Webster]