Taskmaster Tasks

Make the most accurate and inventive egg timer.

Make the most accurate and inventive egg timer. You have ten minutes to plan your egg timer, and then 20 minutes to make your egg timer, after which Alex will boil an egg for as long as your egg timer lasts. The Taskmaster likes his eggs runny, but not too runny. 

You may not use any pre-existing timing devices. 

Your time starts now.