Thanks for the reply, that looks like the David Clark I am after. But found out the mother of (I think) 2 of his children was Jane (or Jean) Samson (not Simpson). The children were William and David Clark and lived with there mum who went on to marry a John Samson. And David Clark appears in the 1871 Census as still living at home, 36 years old, unmarried, Linen Weaver. I will continue my search to complete his details. David Clarks father was Thomas Clark who died in 1847.