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OurStory: Life on the Water Lenses and Lighthouses

Script for the Presentation, page 1 of 3

For adults and kids to explore togethe .

Slide 1: How Things Work: The Fresnel Lens (Image of lens)

Slide 2: Look at page 27 in Keep the Lights Burning, Abbie and compare it to this picture of a Fresnel lens. Do the lighthouse lamps from the book look like the Fresnel lens? (Images of Fresnel lens and book illustration)

Slide 3: Many sources of light, like the oil lamps in Abbie’s lighthouse, send light out that moves in dierent directions. But sometimes, we don’t want the light to go in dierent directions—we want it to go in just one direction, like how lighthouse beams only light up one place at a time. (Image of candle with light going in many directions)

Slide 4: A man named August Fresnel came up with a way to do that using a lens. A

lens is a piece of see-through material (like glass) that focuses rays of light. Say it! FRESNEL sounds like “Fray-nell.” The first part rhymes with “spray” and the second part rhymes with “shell.” (Images of a spray can and a shell, audio recording of pronunciation )

Slide 5: Many lenses are made out of glass or plastic. Looking at this part of a lens

from the National Museum of American History, do you think it is made out of glass or plastic? Hint: It is very heavy and could break! The lens is made out of glass and is held together by a metal called brass. (Image of Fresnel lens with materials labeled)

Slide 6: The Fresnel lens has many parts that have dierent shapes. Each glass part curves just a little bit. Can you count the dierent pieces of glass in this close-up picture of a Fresnel lens? (Image of Fresnel lens with separate parts numbered)

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