I too am interested in the Rev.Cornelius Hallen. My Edinburgh- born wife was a Hallan ( spelling variant ?) before marriage, and her family had a tradition that they were originally Van Hallens. I have been trying to locate, so far unsuccessfully , a copy of " A History of the Hallen or Hallan family... from 1280 till 1882" by the Rev. Cornelius Hallan. I will let you know if I'm successful. I must say it was quite startling to see your site, for I've only just discovered the existence of Cornelius Hallan myself.