Old Dutch        

Quite a nice and early chess clock, dated back to 1920th or 1930th. No makers mark detected, nevertheless, the engineering approach - namely two typical alarm clocks, connected through a pushover bar - brings me to a conclusion, that this is a member of the Old Dutch family. Reference: Fenny Heemskerk (left) vs. Mrs. Roodland (with Max Euwe).

It is a huge (29x18cm) Dutch clock, which belonged to the chess club 'Bilthoven' (Schaakvereen Bilthoven). Based on the clockworks (?Junghans), produced late 1930th. Recognizable from the game of O'Kelly (Hague, 1947).

Another variation of the previous clock, which belonged to the chess club 'De Pion' (Schaakclub De Pion), found in 1929. Production date might also refer to 1930th.

Photo: L.Prins vs. O'Kelly (Netherlands, 1948).

Medium size (18x11) Dutch Zilwo chess clock, characterized by a solid oak wooden box and missing second hands. First evidence of Leeuwarder-based (Netherlands) company 'Zilwo Juwelier' comes from the newspaper advertisement in 1938, latest evidence is the bankruptcy in 1982 (ref: Leeuwarder Courant). When exactly was this chess clock produced (in terms of 40-50 years of company operation) is not known, presumably it should be early post/war 1950th model.