I remember reading Tim Hunkin's cartoon strips many years ago. It was an excellent series about how things work. So I was very pleased to find this water clock. As ever with a clock, energy needs to be delivered to drive an escapement mechanism. This is a system that allows a cog wheel to slip round by one tooth in a regulated amount of time. Filling with water until a tipping point is reached and it emties could be one such way of measuring the time.
