We learned that the Japanese divided days into hours of varying lengths prior to adopting the standard units of the West.  Japanese hours expanded and contracted with the change of season.  How remarkable!

We learned that lead weights and gravity powered pendulum clocks for scores of years.  But if the weights powered these clocks, what purpose did the pendulum serve?  It turns out that the pendulum “incrementalized” into seconds the steady pull of the weight.

We learned that rubies and sapphires historically were used in precision time pieces.  Then what does quartz, a relative newcomer to time-pieces, offer that the gems of earlier watches did not?  Answer:  The jewels of yore (and the synthetic “jewels” of today) serve as bearings.  These tiny spheres allow moving parts to roll over one another, rather than to rub against one another, and thereby reduce friction in clockworks.  Quartz serves another purpose altogether.  When an electrical current is passed through a piece of quartz (as from a battery), it vibrates at an exact rate, which is then translated into seconds, minutes, and hours. 

At another exhibit, second graders pushed a big green “start” button, which electromechanically inverted a large hourglass.  Students then pushed buttons at regular intervals:  button one at the 20 second mark, button two at the 40 second mark, and finally button three at the one-minute mark.  We talked about fractions and estimated how much sand was in the hour glass (90 seconds worth).  We talked about how time may seem elastic (20 seconds is a long time when you are itching to press that button) but we know it is not.  Or, at least we’re pretty sure it is not!

We spent the day admiring the art of clocks, such as a sculpted cathedral clock made of gold.  We considered the engineering of clocks and the science of time.  We smiled at the humor of some clocks:  One clock was shaped like a giant wheel, with each spoke wearing a different boot or shoe that “walked” across the floor of a long, narrow room.  At the far end of the room a gloved stick-hand attached to the wheel pushed a button that caused the wheel to reverse direction and “walk” back to its starting place.  This process took exactly 60 seconds.  It was a clock, of course.