A dog-grate is basically a free-standing fire-basket with vestigial andirons as legs, standing in the hearth against a plain cast-iron fireback. Dog-grates were manufactured in wrought iron, cast iron or bright steel, sometimes with brass or bronze frets and mouldings.
These stretched right across the fireplace opening, although the actual fire-basket occupied only the middle third and was flanked on either side by metal shelving or panels. Unlike the dog-grate, the hob was built into the fireplace; it fitted neatly into the square recess of the opening, the tolerance being taken up with slate, stone or marble slips. The walls of the fireplace above the hobs were usually plastered, although in some cases iron plates or Delft tiles were used to line the recess.
The three usual types of hob-grate, ‘double semi-circle’, ‘double ogee’ and ‘rectangular’, named according to the shape of the ornamented side panels or cheeks, were of cast iron, with bars of wrought iron.
In its early form, a fireplace consisted of a pair of cast-iron firedogs which supported the ends of burning logs above the stone hearth.
A cast-iron fireback, decorated with reeding or a low-relief design, was placed against the wall to reflect the heat into the room.
When in the eighteenth century coal became the standard fuel, many Birkenhead households retained at least one pair of firedogs for occasional wood-burning and these might have carried early coal-burning iron fire baskets; the forerunners of the elegant Georgian dog-grate.