Regulator clocks, the most accurate form of pendulum clocks, were invented in the mid-18th century in a quest for greater timekeeping precision. They were weight-driven devices and featured a deadbeat escapement (an improvement on the anchor design). To ensure their accuracy, they usually omitted complicated features like calendars. Instead, each of the clock’s hands worked off a different mechanism. The Englishmen Benjamin Vulliamy and James Harrison invented two of the earliest regulators between 1760 and 1780. Despite this British lineage, regulator clocks were not especially well received in England, but they were in Vienna, where the form flourished. Indeed, Vienna regulator wall clocks gained such a reputation for accuracy that they were routinely used in public places such as railway stations and post offices. During the Empire period (1800-1835) in Vienna, the cases of antique pendulum wall clocks were typically made of wood, which was either polished or gilded. These laterndluhr clocks resembled three boxes, one stacked on top of the other. The upper part of the case housed the movement and was capped by a roof. The clock’s weights dangled in the center of the case, and at the bottom swung the pendulum. The Biedermeier period (1835-1848) was a very conservative time in Vienna—old pendulum clocks from these years reflected the new austerity. The dachluhr clocks from this era were thus simpler in style. Instead of three sections, these clocks had two: a top section (still with a roof) for the clock’s face and movement, and a bottom section for the weights and pendulum, which could be accessed by a glass door. The clocks were elegant but rigid in their design, except for the "piecrust" bezels around the clocks’ faces. The Viennese revolution of 1848 expanded the middle class, which made luxuries like regulators more accessible to a greater percentage of the population. And after years of aesthetic repression, these newly affluent Viennese embraced revivals of Greek, Renaissance, and Gothic styles. For regulator clocks, this meant that straight sides would give way to serpentine waves. Ornamentation was on the rise, as pediments were interrupted by finials and the sides of regulators were ornately carved and scrolled. As for the dials, they were rendered in creamy, bright porcelain. In 1850s Vienna, antique regulator clocks continued to become increasingly ornate. This meant more finials, more flanking columns, and fancier woodwork on the clock’s top and bottom—walnut, cherry, and other veneers replaced the faux-grain finishes that had come before. Inside the clock, the movement had hardly changed, but pendulum rods were now made of wood and the bezels around the porcelain dials were eye-catching rings of brass. The Vienna regulator clocks from about 1870 to 1895 are the most common today. They are also some of the most ornate and beautiful. Signatures of these regulators include the Corinthian columns on the sides of the cases and the clock’s elaborate hands. All that effusive design ground to a halt at the turn of the 20th century, when the overlapping impulses of Art Nouveau and Arts and Crafts ushered in the Jugendstil style, which was a precursor of sorts to 20th-century modernism. It was a return to the box regulators of almost a century before, but this time the lines were softer, the boxes were less boxy but more massive. In addition, Viennese regulators from this period often featured leaded and beveled glass in front of their swinging pendulums, and the woods ranged from gorgeous maple to rich walnut. In the United States, 19th-century clock manufacturers such as Ingraham, Sessions, Seth Thomas, and New Haven also made regulators. Some of these vintage pendulum clocks were designed like squat versions of the famous banjo clocks that were so popular, others were marketed as "railroad regulators" with train-station style numerals and hands. Just as in Vienna, accuracy was the main selling point for makers of U.S. regulators. Even more interesting, the look of these U.S. clocks paralleled the evolving design of those of the old country, which suggests that U.S. clockmakers were not yet setting the standards for clock design.