> That's because the glass lenses are made such that the little "ribs" in > them are designed to focus the light straight-ahead - obviously, to make > it easier for the engineer to see. If you are not directly in front of > the signal, the brightness will be less. > > - Paul "Little ribs" 8^) Those are Fresnel Lenses http://science.howstuffworks.com/question244.htm http://en.wikipedia.org/wiki/Fresnel_lens http://en.wikipedia.org/wiki/Augustin-Jean_Fresnel Learn something every day, right? SGL The Erie Lackawanna Mailing List http://EL-List.railfan.net/ To Unsubscribe: http://Lists.Railfan.net/erielackunsub.html ------------------------------
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