In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Charterhouse like this:
CHARTER-HOUSE-ON-MENDIP, an extra-parochial ville in Axbridge district, Somerset; adjacent to Blagdon parish, 5 miles E by N of Axbridge. Acres, 2,410. Pop., 82. Houses, 16. It had anciently a cell to Witham Carthusian priory; and it is still ecclesiastically connected with Witham-Friary parish.
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 Charterhouse has changed, please see our redistricted information for the modern district of Mendip. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Charterhouse and units named after it.
GB Historical GIS / University of Portsmouth, History of Charterhouse, in Mendip and Somerset | Map and description, A Vision of Britain through Time.
Date accessed: 30th June 2016
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Charterhouse".