RootsChat.Com

Hi - I've just come across this - four years later -- and want to share this link that may give you some info. You may already have it, but it contains info about the history of Rishton in the Blackburn area, and also mentions Ponthalgh, as there was some relation via marriage between folks of the two places. http://www.archive.org/stream/historyofblackbu00abrauoft/historyofblackbu00abrauoft_djvu.txt

It's a google-scanned book called the History of Blackburn. The pages of interest will be around 634+