About This Puzzle
Did you know? In 1823, the first Fresnel lens was installed at the Cordouan Lighthouse, allowing its light to be seen from more than 20 miles (32 km) away — a revolutionary leap over earlier parabolic reflectors, which focused only 20% of a lamp's light compared to the Fresnel lens's 85%. Source
Photograph by Neeraj Pramanik via Unsplash.
Estimated Solve Times
- 10 pieces: Under 1 minute
- 36 pieces: 3-6 minutes
- 64 pieces: 8-15 minutes
- 100 pieces: 15-30 minutes
- 200 pieces: 35-60 minutes
- 400 pieces: 1-2 hours
