Science Museum, London
Science Museum: Online Stuff: Huygens' Clocks
Find out about Christiaan Huygens who built the world's first pendulum clock in 1656. The pendulum clock became the most accurate clock in the world for nearly 300 years.
TryEngineering
Try Engineering: Pendulum Time
Working in teams, students build their own pendulum clock using everyday materials. They conduct research, design, build, test it, and share observations with the class, while learning how pendulums operate and have been used to measure...
The Franklin Institute
The Franklin Institute: Clocks Teaching Time
This site from The Franklin Institute presents a number of activities, games, exhibits, scavenger hunts, resources, links related to clocks and telling time.
TOPS Learning Systems
Tops Learning Systems: Top Science: Clock Pendulum [Pdf]
Create a clock that accurately keeps time using a pendulum.