Augustin-Jean Fresnel -- Fresnel Lenses

A Fresnel lens ( fray-NEL or FREZ-nel) is a type of lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.


Augustin-Jean Fresnel
This work is in the public domain

♥Augustin-Jean Fresnel, a nineteenth century physicist, the son of Jacques Fresnel and Augustine Mériméewas was born in France on May 10, 1788. He died of consumption at Ville-d'Avray, near Paris, on the 14th of July 1827. He was the son of an architect,
*He may most often remembered for the invention of unique compound lenses designed to produce parallel beams of light, which are still used widely in lighthouses. Fresnel's early education was provided by his parents and he was considered a slow learner, barely able to read by the age of 8. When he was 12-years-old, however, Fresnel began formal studies at the Central School in Caen, where he was introduced to the wonders of science and demonstrated an aptitude in mathematics.
♥He served as an engineer. His researches in optics, continued until his death, appear to have been begun about the year 1814, when he prepared a paper on the aberration of light, which, however, was not published. In 1818 he read a memoir on diffraction for which in the ensuing year he received the prize of the Académie des Sciences at Paris.
*Although he received little public recognition for his efforts during his lifetime.
♥He was in 1823 unanimously elected a member of the academy, and in 1825 he became a member of the Royal Society of London, which in 1827, at the time of his last illness, awarded him the Rumford medal. In 1819 he was nominated a commissioner of lighthouses, for which he was the first to construct compound lenses as substitutes for mirrors.
*n the field of optics, Fresnel derived formulas to explain reflection, refraction, double refraction, and the polarization of light reflected from a transparent substance. Fresnel also developed a wave theory of diffraction. He created various devices to produce interference fringes in order to demonstrate the interference of light wavelets. Using his inventions, Fresnel was the first to prove that the wave motion of light is transverse. He accomplished this task by polarizing light beams in different planes and showing that the two beams do not exhibit interference effects.
*In 1822, Fresnel invented the lens that is now used in lighthouses around the world. The Fresnel lens appears much like a giant glass beehive with a lamp in the center. The lens is composed of rings of glass prisms positioned above and below the lamp to bend and concentrate the light into a bright beam. The Fresnel lighthouse lens works so well that the light can be seen from a distance of 20 or more miles. Before Fresnel's invention, lighthouses used mirrors to reflect light, and could be seen only at short distances and hardly at all during foggy or stormy days. Lighthouses equipped with Fresnel's lenses have helped save many ships from going aground or crashing into rocky coasts.




Chart of Fresnel Lenses

Order Height InsideDiameter
First 7' 10" 6' 1"
Second 6' 1" 4' 7"
Third 4' 8" 3' 3"
Third and 1/2 3' 0" 2' 5 1/2"
Fourth 2' 4" 1' 8"
Fifth 1' 8" 1' 3"
Sixth 1' 5" 1' 0"




This image is from:
Biloxi Lighthouse



A First Order lenses is huge! It can be 12 feet tall and 7 feet in diameter.

Click image for larger view

Makapuu Point Lighthouse -- The largest lens used in the U. S. Lighthouse Service
The inside diameter is 8 3/4 feet.
--Exp. of size of first order lens--

This Sixth Order lens is the smallest of the lenses made for lighthouses. A sixth order can be as small as 1 1/2 feet tall and be seen for 5 miles.


¹A fixed Fresnel lens sends light beams in all directions all of the time. The light does not flash.

¹A revolving Fresnel lens sends light beams (which look like a flash) in specific directions

Lenses were classed based upon the distance of the light source to the lens. The sizes ranged from the largest first order to the smallest sixth order.
Prior to the introduction of the Fresnel lenses, lighthouses had many individual oil lamps, as many as fifteen or twenty at a major seacoast light. Not only did these consume a tremendous amount of oil, but they weren't all that bright, and couldn't be seen from very far away.


First Order Fresnel Lens
Used with permission of author Gabelstaplerfahrer


Second Order Fresnel Lens
Description: The lens is 4’8" in diameter and 6’8" in height. It is larger than a second order (4’7" by 6’1") lens, but smaller than a first order (6’1" by 7’10") lens.
Use with permission of author Cacophony


Third Order Fresnel Lens
Description: Former Fresnel Lens of Anacapa Island Lighthouse (California, USA). Quote: "For nearly 60 years and 52 million rotations, the Fresnel lens and light warned sailors away from Anacapa's rocky coast." - NPS.
Author National Park Service


Third and 1/2 Order Fresnel Lens
Description:This is a picture of the last fresnel lens to operate in Marblehead Lighthouse. It is a 3 1/2 order lens. It was in operation at the lighthouse from 1904 - 1969. It is now on display inside of the Marblehead Lighthouse musuem.
Used with permission of the Author Matt Dempsey from Lorain, Ohio, United States of America


Fourth Order Fresnel Lens
Used with permission of author Pictowrit


Fifth Order Fresnel Order Lens
Description - English: Fresnel lens of Loschen-Lighthouse in Bremerhaven, Germany;
Used with permission of Author Hannes Grobe 06:12, 30 July 2006 (UTC)

To view more and diffrent lens visit here:
Point Arena Lighthouse



♥This info is from:
NNDB

*This info is from:
Molecular Expressions
Science, Optics and You


¹ LighthouseCurrriculm Grades K-4
An educational service provided by
The United States Lighthouse Society







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