Thanks Chris. All I know of my Polkinghorne connection is that my gg grandmother, Mary Ann Kemp, was born to Thomas Kemp and Mary Polkinghorne in Lamorran, near Truro in 1846. I believe she was their first child. She came as a 19 year old with her husband, young son and parents to South Australia in 1865. A connection with your family looks a bit remote, but who knows.