Thank you Frances, that was also very clear & helpful. I begin to feel that these information treasure houses might be accessible to me after all, and I might make interesting progress in my family history. I'm quite excited by the prospect. If only I could find Wood's atlas on-line or in the bookshop!

Just one thing, when you say 'see book of mortgages' is that what it's actually called, or is it part of something else?

Thanks again.