The curfew bell was a famous institution; but the name was not originally applied to the bell itself. This leads to another curious bit of domestic metal. The popular idea of a curfew is that of a bell; a bell was undoubtedly rung at the curfew hour, and was called by its name; but the actual curfew (or _couvre feu_) was an article made of copper, shaped not unlike a deep "blower," which was used in order to extinguish the fire when the bell rang. There are a few specimens in England of these curious covers: they stood about ten to fifteen inches high, with a handle at the top, and closed in on three sides, open at the back. The embers were shovelled close to the back of the hearth, and the curfew, with the open side against the back of the chimney, was placed over them, thus excluding all air. Horace Walpole owned, at Strawberry Hill, a famous old curfew, in copper, elaborately decorated with vines and the York rose. [Illustration: A COPPER "CURFEW"] [Illustration: SANCTUARY KNOCKER, DURHAM CATHEDRAL] The Sanctuary knocker at Durham Cathedral is an important example of bronze work, probably of the same age as the Cathedral door on which it is fastened. They both date from about the eleventh century. Ever since 740, in the Episcopate of Cynewulf, criminals were allowed to claim Sanctuary in Durham. When this knocker was sounded, the door was opened, by two porters who had their accommodations always in two little chambers over the door, and for a certain length of time the criminal was under the protection of the Church.