There are many ecclesiastical emblems visible during a morning stroll through the streets of London. Among those readily seen are the key vane on St. Peter's, Cornhill, and the emblematic gridiron on St. Lawrence's Church. On St. Michael's Church, Queenhithe, there is a copper ship, the hull of which holds just one bushel of grain. This vane is interesting in that the emblem has reference to Queenhithe, once a famous wharf, rather than to the patron saint. The Hithe is interesting in its old associations, in that the tolls of that wharf were given to Queen Eleanor by Henry II as pin money, subsequent queens of England collecting the revenue for their personal use. The grasshopper on the Royal Exchange is the same vane that surmounted the more ancient building which preceded the one now standing. The grasshopper was the crest of Sir Thomas Gresham, by whom the first Exchange was built in the reign of Queen Elizabeth. This vane, also of copper, is fully 11 ft. in length, and in miniature was reproduced as the sign of the banking house in Lombard Street kept by Sir Thomas Gresham. The Door Knocker. The common door knocker, essentially a piece of metal associated to-day with utilitarian purposes, is not without romantic associations. It has been a much collected object; easily detached, too, for it is said that many of the old knockers, or rappers as they were formerly called, which a few years ago could be bought quite cheaply from the marine store dealers, had been surreptitiously purloined by thieves, who for the sake of a few coppers had taken some risk even on a dark night. Some old houses are still rich in antiquarian door knockers, before the days of front door bells and electric pushes more a necessity than they are now. Their use was by no means confined to private houses, on which they figured in a variety of forms, but among the earlier examples are ponderous knockers of copper and brass, once regarded as an essential feature on the great oaken doors of cathedrals and churches and other important buildings. In the days when the precincts of certain ecclesiastical edifices were sanctuary, the knocker was the goal sought by the criminal offender who rushed to obtain the protection of sanctuary. One of the most famous historical knockers which has been copied by modern founders, and is seen in collections of so-called antiques and in use as a modern replica on room doors in twentieth-century houses, is the famous knocker which did service for so many years on the Sanctuary door of Durham Cathedral. It is a relic of great antiquity, having been placed on the door prior to the reign of King Stephen. Detailing its use as sanctuary a contemporary monk wrote: "Hereupon their leader violently and repeatedly struck the brass rings which hang outside the door." According to the "rights" of Durham all the churchyard and all the circuit thereof was sanctuary for all manner of men whatever their offences had been. It will be remembered