Imagine using a Fresnel lens as a coffee table! That is exactly what happened in Oakville, ON when their lighthouse was replaced by a modern aid to navigation in 1960. Now sitting in a local museum, the Fresnel lens minus coffee mugs looks remarkably good but no one knew what order (size) it was. The same thing happened in an open house at the Akaroa Lighthouse in New Zealand. The guides didn’t even know the lens came in different sizes! So much for “The Invention that Saved a Million Ships”, an article by Adrienne Bernhard! The concept of such a lens was proposed in 1748 but it was only in 1822 that the civil engineer, Augustine Fresnel, fabricated the first lens. Many NS lighthouses replaced their simple reflector for this complex lens that shone a brilliant light when the lamp was lit inside it. A first order Fresnel lens is the biggest made and the one removed from Sambro Island Lighthouse in 1967 now sits in the reception area of the Maritime Museum of the Atlantic. (fb)

You have heard about twinned cities, but what about twinning lighthouses? Gabarus on the eastern side of Cape Breton Island is Nova Scotia’s only hexagonal (6-sided) lighthouse built in 1890 for $650. Big Tub Lighthouse at Tobermory on Georgian Bay, Ontario is also hexagonal and was built in 1895 for $675. Why the $25 difference? Gabarus stands 9.7 metres tall while Big Tub measures 13 metres high. Both have fixed red lights and switched from oil to hydro around the same time in the early 1950s. These two lighthouses are also subject to the forces of nature: Gabarus was moved back from an eroding cliff in 2015 while Big Tub had part of its foundation washed away by a wild winter storm in 1987. Still active aids to navigation, Gabarus shines year round while Big Tub is a seasonal light. As for federal heritage, neither got Heritage Lighthouse Protect Act (HLPA) designation in spite of having much support from local community groups. A business plan to support them financially is a HLPA requirement but regretfully none to date have been proposed. (fb)