The Lost Lens

For sixty-four years, a fifth-order Fresnel lens made by Henry-Lepaute of Paris lit the Portage River Lighthouse. When the light was retired in 1920, the lens left, and no one has been able to tell us where it went. We are looking for it, and we would love your help.

 

What the lens was

A Fresnel lens bends and gathers lamplight into a beam with rings of glass prisms instead of one thick lens. They came in sizes called orders, from the huge first order on major coastal lights down to the small sixth. A fifth-order lens was a harbor light: small enough for a tower like ours, strong enough to be seen across the bay. (more on Fresnel lenses)

 

Ours came from Henry-Lepaute, one of the great Paris lens makers. It was installed in the first tower in 1856 and moved into the new lantern in 1869 to 1870.

 

What made ours different

The Portage River light did not just shine. It flashed red.

 

The lens gave a steady white light, and around it turned a carriage of flash panels that swept a red flash across the bay. Ships could tell this light from any other by that pattern.

 

• 1856 to 1891: a red flash every two minutes.

• From August 15, 1891: a red flash every minute.

 

On a clear night the light carried about eighteen miles.

 

What we know about where it went

• The light was discontinued on August 1, 1920.

• The lens was removed at some point after that. We have found no record of when, by whom, or where it was sent.

• Lenses from retired stations were often reused at other lights, stored at Lighthouse Service depots, or given to museums decades later. Ours could be in any of those places, or in a private collection.

 

Where we are looking

• Lighthouse Service and Coast Guard records at the National Archives

• The U.S. Coast Guard Historian's Office

• The United States Lighthouse Society

• Great Lakes maritime museums and their collections

• Michigan Tech Archives and Copper Country Historical Collections

• Old photographs of the lantern room, which could show the lens's exact shape and markings

 

How you can help

Do you know anything? A family story, a photo taken inside the lantern before 1920, a museum lens labeled only "fifth order, Henry-Lepaute," an old Lighthouse Service record, anything at all. Write to us at Keeper@PortageRiverLighthouse.com. We will credit every lead we follow, and if the lens turns up, you'll hear about it first.

 

Want updates on the search? Join the newsletter. Every month's Keeper's Log includes where the hunt stands.

 

More about the light itself: the history of the Portage River Lighthouse.

 

 

Frequently asked questions

What lens did the Portage River Lighthouse have?

A fifth-order Fresnel lens made by Henry-Lepaute of Paris.

 

What was its light pattern?

Fixed white with a red flash, every two minutes until August 15, 1891, then every minute.

 

Where is the Portage River Lighthouse lens now?

Unknown. It was removed after the light was retired in 1920, and the owners are searching for it.

 

Is there a light in the tower today?

Not as a navigation light. A small antique lamp glows in the lantern room for atmosphere, but it is not an aid to navigation. We are applying to have the Portage River Lighthouse recognized as one again, and we are choosing a modern beacon for the job. If the original lens turns up, we would love to see it back where it belongs, even if a modern light does the working.

 

 

Sources

• Lighthousefriends.com, "Portage River (Jacobsville) Lighthouse," citing the Annual Reports of the Lighthouse Board.

• Portage River Lighthouse, "Guiding Lights: The Remarkable Fresnel Lenses" (Nov 4, 2023).

 

Last reviewed: November 2026