I can confirm that Joseph MASON, was in fact a base child born to Zilpah MASON. This is my direct line - Thomas and Zilpah are my 3rd Great-Grandparents. I secured a copy of Joseph's birth registration from the GRO, and it lists no Father. In the "Name and Surname of Father" space is written "Illegitimate". No clue who might be the Father of Joseph. (Yet!)