might I suggest purchase of a map - the public rights of way is 1:25000 and available for less than £10 via Museum shop - I also understand that the 6in/mile pre 1900 O/S maps are free online and I think accessible via Google - MNB has placenames - the MNB CD rom also has the original 1"/mile O/S map of 1868/9 (a reprint of which is also on sale at Manx Museum shop)

Thanks Frances, you reminded I have indeed got a public rights of way 1:25000 map.

A couple of stumbling blocks though -

the print is tiny and very hard to read even with glasses. Maybe what I actually need to buy is a magnifying glass!

I'm not sure of the exact boundaries of the parishes, but have searched between the River Neb, Kirk Michael, Beary Mountain and Greeba and not spotted what I'm looking forward, except that I found a Ballachrink near St John's.

The addresses I had for online old maps don't seem to work any more.

I have looked on MNB and have found mention of Northop but haven't been able to spot it on the map yet.

As I'm not sure what it actually says in the 1851 census it's hard to find the location - there are quite a few places beginning 'Bal'. I think if I had someone else's reading of that place name that would be the biggest help for me to track it down.

Thanks again.