We drove down to Bath and Brunswick Maine this morning. Our only touring stop was the Maine Maritime Museum, on the site of the Percy and Small shipyard which manufactured the Wyoming, a six masted schooner designed to haul coal. Built in 1909, it was the largest wood sailing vessel ever built. The museum is well done and our docent led tour was very informative. There is a steel sculpture on the grounds which presents the size of the Wyoming. There were two exhibits that caught my eye. The first was a triple expansion steam engine. I have seen them before and always wondered how the worked in practice. The theoretical part is pretty obvious. We are going back tomorrow so I might find someone there to explain.

The second item was a second order Fresnel lens which was in the Cape Elizabeth light station until 1995. What I found interesting was there were six flash panels on 180 degrees of the circumference and "Eclipse" panels on the remainder. The eclipse panels are prisms which reflect the light back into the lens and appear unlit from the outside. That was a new one on me.

Today's photo is of the lens just as it rotates from the last flash panel onto the eclipse panels.