Antique and Vintage Mechanical Clocks

The 400-day anniversary clock, also known as long-duration clocks, is a fascinating category of clock known for its ability to run continuously for a full year without needing to be wound. These clocks, often featuring intricate designs and beautifully crafted mechanisms, were first introduced in the late 19th century and have since become a beloved collectible.

In this article, we’ll explore the history, mechanics, and appeal of these interesting clocks. This is a two-part series. The first part describes my most recent purchase, a 400-day Kundo anniversary clock. Part II involves the installation of the suspension spring, cleaning, testing, and post adjustments.

400-day clocks are known for their inaccuracy, although they are undeniably beautiful and fascinating to observe. A minute lost each day adds up over the course of a year, potentially totaling many minutes—or even hours—by the end. Despite this, I still find great joy in owning and appreciating them.

A brief history

400 day clocks have been with us since about 1900. There were torsion clocks produced before 1900 but in limited numbers from about 1894 onward but the real push was after 1900. The Kundo model you see here was made in the late 1950s or early 1960s, probably the peak and subsequent decline of the anniversary clock era.

Once quartz clocks were introduced mechanical versions declined precipitously. Kundo is one of many companies making anniversary clocks in the 1950s and 60s. Kundo is a combined form of Kieninger and Obergfell. The company exists to this day as Kieninger, a subsidiary of Howard Miller which is part of a larger company.

This particular clock is a good example of a typical anniversary clock of the period. There are signs of wear as one might expect, dents on the base where an unrestrained pendulum did its damage and a snapped suspension spring but all the parts are there, complete with its dome.

The clock was purchased at a local antique store. It is not in running condition. These clocks typically sell for around $50 to $100 or more on online marketplaces. Domes are often chipped or missing entirely. The glass dome on this one is free of chips.

I have ordered a Horolovar spring  (.0032″) and will report on the installation, cleaning, and testing of this 400-day clock. Look for the second part of this series.