« Harder and the 400-Day Clock »
With his invention of a pendulum clock that needs winding only once a year, Anton Harder created a design that is especially popular for its visual appeal. That was not always the case, however. Read on for revealing insights into the history of this clock and the man behind it, Anton Harder.
As in many other fields of science and technology, the history of horology has had its share of inventive minds who were far ahead of their time and conceived clocks that could only be built in series once technology had matured and advanced further. Anton Harder was one such pioneer. His torsion pendulum clock, also known as the anniversary clock or 400-day clock, was a creation that only belatedly received the attention it deserved.
Anton Harder – Farmer, Traveler and Inventor
Anton Harder was born in Saint Petersburg on September 16, 1811. His family was originally from Germany and had followed the invitation manifesto issued by Catherine II, which promised freedom of religion, freedom of language, self-government and other privileges. Harder's ancestors thus settled first in Reval and later in Saint Petersburg, where they worked mainly as merchants and physicians. Anton Harder himself initially took up farming because his father-in-law wished it. When the Franco-Prussian War ended in 1871, Harder traveled to France, where he conceived his great idea. According to tradition, he was lying on the heights above the Meuse, looking out over the former battlefield of Sedan and reflecting on the Germans and their history.
He plucked at a blade of grass sprouting from the ground. Because the base of a shrapnel shell was still attached to its root ball and the blade had worked its way through it with a twisting motion, this small observation provided the inspiration for the invention of the torsion pendulum. Harder returned to his estate in Silesia and set up a clockmaking workshop in one wing of the house, where he put his ideas for the torsion pendulum clock into practice.
The Torsion Pendulum Clock
It was not all that long ago, in the early 1980s, that modern versions with a torsion pendulum came into fashion. In these, the pendulum with its balls still rotated around its axis just as in a genuine torsion pendulum clock, but it served no real purpose, since the hands were usually driven by a built-in battery. Nevertheless, it was a highly attractive feature that proved very popular with clock lovers. As a result, many households had such an anniversary clock on a shelf, mantelpiece or table, where its unique beauty was much admired. The original torsion pendulum clocks, however, date back almost 150 years. Their inventor, Anton Harder, received the patent for the torsion pendulum in 1877 together with Lorenz Jehlin. Even so, it took almost twenty more years before series production became possible.
At the beginning of the twentieth century, the 400-day clock, or anniversary clock – as the torsion pendulum clock was also called – was a popular clock in Germany as well as in Great Britain and the USA. The torsion pendulum with its four small balls, which rotates at a rate of either 30 or 15 seconds and thus provides the drive, was already something very special at the time. However, anniversary clocks of that era frequently had to be readjusted, as they were not particularly accurate.
How Does a Torsion Pendulum Anniversary Clock Work?
The actual running time of a torsion pendulum clock is not always exactly one year; with some models it is somewhat longer or shorter. Yet such a timepiece is very popular for its torsion pendulum alone. This performs the same function as the pendulum of a classic pendulum clock, except that the weight does not swing back and forth but rotates around a rod. The torsion pendulum, as it is also called, supplies the movement with the necessary drive. For the clock to run for a year, the pendulum's friction must be kept as low as possible. At the same time, it oscillates much more slowly and therefore also consumes less energy.
The torsion pendulum consists of a rotating weight suspended from a flat metal band. This ensures extremely low friction, similar to the balance spring of a watch driven by a balance wheel. As the pendulum weight rotates, it twists the metal band, which provides a force counteracting the rotation and can be kept very small. As a result, each oscillation of a torsion pendulum takes considerably longer, and the clock runs longer. As a rule, the torsion pendulum takes 15 or 30 seconds for one rotation. To change the frequency of the oscillation, the mass of the torsion pendulum must be changed. On models with four oscillating balls, the anniversary clock can be regulated via the distance between the balls. On older versions, the mass may also be a flat disc fitted with two regulating weights that can be adjusted by means of a threaded rod.
The Belated Success of the Torsion Pendulum Clock
Harder and Jehlin had developed the torsion pendulum with a leaf-spring suspension and filed for a patent in Berlin in 1877. Since Jehlin died shortly afterward, his father, as heir, transferred the patent rights to Harder. Harder then looked for a company to manufacture an anniversary clock with a torsion pendulum and found it in Willmann & Co. in Freiburg, Silesia. Willmann produced around 300 examples of the 400-day clock, but many customers complained about its lack of accuracy. A. Willmann & Co. therefore discontinued production from 1881. Other clock companies also tried their hand at making the 400-day clock, but the design flaws remained.
The first truly functional anniversary clocks were made in 1882 by the firm Wintermantel & Co. A year later, Anton Harder sold his patent to the Dutch merchant Ferdinand Arnold Ludwig de Gruyter, who had these special clocks produced on a large scale. Harder died in Steinau in 1888 and sadly did not live to see the anniversary clock he had developed become a real success in the years that followed, manufactured on a large scale by various companies according to his vision.
