they weren’t using the special Fresnel-style lenses. There had been speculation about building this type of lens, but Fresnel was apparently unaware of them when he proposed his lens for ...

Making a traditional glass lens requires a lot of experience, skill, and patience grinding a piece of glass to the required shape, and is not for the casual experimenter. Making a glass Fresnel ...

Fresnel lenses are all around us, but this vase puts the commonplace technology to work in an entirely new way. Borrowed From Old Lighthouses, A Method For Super-Powerful Solar Power With the help ...