Application The Sixth Order lens, the smallest of the regular Fresnel Orders, was used in minor lights, showing the line of branch or secondary channels or the ends of piers, breakwaters and jetties. One of these lenses was used in the Cheboygan Front Range Light. Specifications: |
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| Lens height: | 17.05" | |
| Focal length: | 5.9" | |
| Weight of assembly: | 220 lbs | |
| Relative brightness (over sixth order): | 1x | |
| Useful range: | Up to 5 nautical miles | |
| Number in US lighthouses in 1884: | 123 | |
| Number in US lighthouses in 1922: | 65 | |
| Oil consumption per hour: | 3.14 oz. | |
References Annual Report of the Lighthouse Board, 1884 The United States Lighthouse Service, Dept of Commerce, 1915 Aids to Navigation Manual, US Coast Guard, 1945 Comparative Table of Lens Orders, Mabel A. Baiges, 1988 Letter from Helen & Al Gademsky, 07/02/01 |
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