England showing Port of Spain c.d.s., "POST FREE/P.C./PRISONERS OF WAR" and "MILITARY CAMP/Trinidad, B.W.I." circular cachets in violet. Photo" /> cover 1916 (1 Apr.) printed P.O.W. envelope addressed to<I> "Whitfield King"</I> England showing Port of Spain c.d.s., "POST FREE/P.C./PRISONERS OF WAR" and "MILITARY CAMP/<I>Trinidad, B.W.I."</I> circular cachets in violet. Photo | Christie's