How did the clock chime?

This is where the science more or less ends. We made a float that rose as the water level moved up in the lower barrel. By using bamboo, string, nails, scraps of wood and other odds and ends we linked this to a triggering mechanism which released coconuts or calabashes on the hour so that they would roll down rails to make a chiming noise on an old disused lime juice machine. Perhaps we were out in the tropical sun for too long! To calibrate the water clock, we used the sundial and worked out how far the float rose each hour.

Making a "watch" 

Major funding for Rough Science was provided by the National Science Foundation. Corporate funding was provided by Subaru.

Copyright © 2002 The Open University and WETA.