Think I've found them in 1871 in Carlisle, in what looks like a lodging house. Indexed as Prat - possibly one of those funny es that look like rs, although other es on the page are 'normal'
Barwise Court, Blackfriars Street,
RG10/5217/42/30
Elizabeth Hetherington, 65, b. Cumberland
...
....
Mathew Prat, lodger, 27,sawyer, b; Scotland
Flora Prat, lodge, 26, b. Scotland