Julien Coyne invented a digital sundial. Sundials usually cast a line or triangle to indicate the hour. This one is designed so that when light passes through, it displays the shapes of numbers.

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IN these days of accurate clocks and watches no one thinks of using a sun dial to tell the time of day. At best such an instrument can be right but four times a year, and in many places it can ...

Sundials and shadow clocks were being used ... In medieval China, you could smell the time Fire clocks were used in medieval China and Japan. Incense sticks or powders were calibrated to burn ...