Kern & Sohne Clock Company was formed in 1937 by Karl Kern and his sons. The company produced mainspring-driven 400-day "anniversary clocks" up to 1985. The 400-day clocks manufactured by various companies have similarities which, at first impression, can be difficult to identify if the brand is not noted on the dial. Since 400-day clocks are shielded with a clear glass dome, identifying the Kern & Sohne clock requires no special skills or tools.
Check the dial. This is the most expedient method of identifying a Kern & Sohne clock. On some clocks, only the name "Kern" may be present on the dial.
Check the back plate of the clock for further verification.
Examine the lower right-hand side of the back plate for the name "Kern & Sohne" engraved into the brass.
Look at the lower left side of the back plate for a conspicuous circle with the letters "KS" within it. Immediately below the circle, check for the word "Germany."
Circles that surround the letters "KS" may have incremented lines around the circumference or a double-ring circle with lines between the two rings. A clock purchased for parts or restoration that has no dial can be identified by markings found on the back plate. Most Kern & Sohne movements have a version of the KS logo on the back plate, unless the plate is marked with "K.u.S" followed by the movement reference number.