The pendulums in grandfather chime clocks have a weight or 'bob' suspended by a rod, the bob is usually a smooth disk that is lens shaped for air resistance and the weight of the 'bob' is as heavy as the suspension can support and the movement apparatus can drive. This improves the clock's accuracy.
The 12 hour chime clock eventually set the standard, but there was a time when 24 hour chime clocks were prevalent. One type of chime clock even used "Roman Striking", a high tone and a low tone to tell the time, instead of the traditional count of chimes to determine the time of day. For instance, the hour of four is represented by one high tone followed by a low tone, whereas the eleventh hour would be two low tones followed by one high tone. Chime wall clocks, grandfather clocks (click pic to enlarge) give us more than home decor and telling the time, they give as a sense of history, nostalgia, and family ties. Find just the chime clock that does it all for you. There's great selection and value to be found, by visiting WindSongWindChimes.com.