In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Buttermere like this:
BUTTERMERE, a parish in the district of Hungerford, and county of Wilts; 4¾ miles S of Hungerford r. station. Post Town, Shalbourn, under Hungerford. Acres, 1,502. Real property, £906. Pop., 12 8. Houses, 26. The living is a rectory in the diocese of Salisbury. Value, £229. Patron, the Bishop of Winchester.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Buttermere has changed, please see our redistricted information for the modern district of Kennet. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Buttermere and units named after it.
GB Historical GIS / University of Portsmouth, History of Buttermere, in Kennet and Wiltshire | Map and description, A Vision of Britain through Time.
Date accessed: 09th March 2014
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Buttermere".