Split Rock Lighthouse: The Magnificant Lens
Split Rock Lighthouse was equipped with a 3rd order, bi-valve type Fresnel lens that was manufactured by Barbier, Bernard and Turenne Company in Paris, France. It is a combination of glass prisms and a brass framework.
Although extremely heavy, the lens floats on a bearing surface of liquid mercury. This magnificent lens is almost 100 years old and is the original lens. It can be seen by climbing to the watchroom level of the tower. During visiting hours, the clockworks is kept "wound" so you can watch the lens rotate.