A medieval bowman describes the more powerful heavyweight crossbow which uses a complex windlass mechanism to load it.

This live-action video program is about volcanoes. The program is designed to reinforce and support a student's comprehension and retention of the word through use of video footage, photographs, diagrams and colorful, animated graphics...

The $0.5 billion James Webb Space Telescope became a $10 billion device when NASA spent billions to fix the design of its giant sunshield’s deployment mechanism.

The video discusses different types of volcanoes and how they are formed based on different types of volcanic eruptions. It covers four main types of volcanoes: cinder cone, shield, dome, and composite (or stratovolcano). The video also...