What were they carved on?
The slates in question come in a variety of sizes. Some consist of hugh horizontal slabs above the kitchen range. These can be 7 foot 6 inches by 1 foot 8 inches in size, flanked by two slightly smaller uprights.
In bedrooms and parlours horizontal slates 4 foot by 1 foot with matching, or slightly smaller, uprights were the norm.
There are also a few narrower 5 foot by 5 inch slates in existence, carved in the same fashion, which stood originally between the feet of the dresser on the 3 inch high dampproof plinth, on which best furniture stood. Some times the edge of the plinth is similarly carved.
A variety of small items were carved such as miniature chests of drawers, probably used as door stops, and minature Grandfather Clocks, books etc used as ornaments.