In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Cemais like this:
KEMEYS-INFERIOR, a parish in Newport district, Monmouth: on the river Usk, 3 miles NE of Caerleon, and 4 N by E of Llanwern r. station. Post town, Caerleon, under Newport, Monmouth. Acres, 1, 676. Real property, £1, 689. Pop., 122. Houses, 22. The property is divided among a few. More than a third of the area is woodland. Stone for paving and for roofing is quarried. The living is a rectory in the diocese of Llandaff. Value, £130. Patron, the Rev. W.Risley. The church is good.
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 Cemais has changed, please see our redistricted information for the modern district of Newport. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Cemais and units named after it.
GB Historical GIS / University of Portsmouth, History of Cemais, in Newport and Monmouthshire | 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 "Cemais".