Before electricity made doorbells ubiquitous, people used to announce their arrival at a friend or stranger’s front door by lifting a heavy cast-iron, brass, or bronze door knocker and rapping it smartly against the contraption’s strike plate. Some door knockers (also spelled “doorknockers”) were designed in the shapes of faces and animal heads, while others were fashioned in the prevailing style of the day, from Arts and Crafts to Art Nouveau. But whatever their appearance, the sound they made would invariably trigger the barking of dogs followed by approaching footfalls. In other words, they worked. They were often quite beautiful, too, which makes sense considering the first-impression impact they were designed to have. For example, cast-iron rococo door knockers from mid-18th-century France were built of multiple curlicues, with lone flat spots reserved for the points of contact between striker and strike plate. This, the knocker seemed to say, was the home of a family that valued style. Similarly, the Duke of Wellington’s victory over Napoleon at Waterloo in 1815 spurred English metalsmiths to create a door knocker that featured a small lion’s head at the bottom of a laurel garland, whose pivot-point was gripped by a cast-iron fist. This, the knocker appeared to proclaim, was the home of patriots. In general, there were three types of door knockers—hammer knockers, figurative knockers, and rings. Hammer knockers pivoted on a plate that sometimes extended below the end of the knocker to serve as its own striking surface. Other types of hammer knockers were attached to a smaller plate at the top, which meant a separate strike plate had to be installed in the door to keep it from being dinged by the knocker’s business end. Freemansons even made hammer knockers in the shape of hammers. The designs of hammer knockers ranged from decorative shapes taken from nature and geometry to figurative ones, most famously in the brass, Victorian Era ladies hand, which held a heavy brass ball that clanked loudly when knocked against its companion circular strike plate. Even more historic were the wrought-iron fleur-de-lis door knockers formed from flat bands of hammered metal—the weight of the inwardly scrolling end of the band made a fine striker. Figurative knockers incorporated everything from lion heads (a British favorite) to eagles (popular in the United States) in their designs. Sometimes the figure, or even just its head, was incorporated into the knocker’s plate—those lion-head knockers, for example, often held strikers in their jaws. Other figural knockers used the animal itself to form the striker—an elephant’s head and trunk makes a perfect door-knocker striker. Medusa heads and other mythical caricatures were also popular. Rings, such as those held in a lion’s jaws, often had a ball of metal on the insides of their bottom-most points, to give the shape weight and increase its volume when rapped. Some rings were stirrup shaped and thicker at their bottoms to give them heft while others resembled twisted strands of rope. Garlands, braids, and horseshoes are other examples of ring-style door knockers. One type of door knocker that’s coincidentally of interest to collectors of postal antiques incorporates a mail slot into its design. Usually the slot is positioned horizontally, with the word “Letters” embossed across the face of its hinged flap. But some are vertical, which means the striker would have to be designed so that it, too, had a slot, lest it made the mail slot behind it useless.