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General => History => Topic started by: Icarus on November 30, 2023, 03:35:23 AM

Title: Fresnel lenses and Lighthouses
Post by: Icarus on November 30, 2023, 03:35:23 AM
This section has been quiet for a long time. Here is my effort to give it a small boost. History is fun.......sometimes.

Title: Re: Fresnel lenses and Lighthouses
Post by: Dark Lightning on November 30, 2023, 03:57:59 AM
Cool!
Title: Re: Fresnel lenses and Lighthouses
Post by: hermes2015 on November 30, 2023, 08:32:08 AM
Thanks, Icarus. I enjoyed watching that.
Title: Re: Fresnel lenses and Lighthouses
Post by: Recusant on November 30, 2023, 05:05:36 PM
Haven't watched the full video yet. From having spent my younger years on the actual coast of the west coast of North America and visited a few lighthouses there and elsewhere, I've been lucky enough to see a variety of Fresnel lenses. I think they have remarkable charisma in person.  :smokin cool:
Title: Re: Fresnel lenses and Lighthouses
Post by: Asmodean on December 04, 2023, 02:24:44 PM
I've read (I think, though quite possibly watched) that they used quicksilver bearings for those lenses to turn and that those bearings would be cleaned out, possibly by hand, by the keeper.

I suppose that was before humans had what little respect for heavy metals they do today, but still... A bloody open-air quicksilver bearing!

(I must admit to not yet having watched the video - perhaps it is addressed therein?)
Title: Re: Fresnel lenses and Lighthouses
Post by: hermes2015 on December 05, 2023, 12:19:08 AM
Quote from: Asmodean on December 04, 2023, 02:24:44 PMI've read (I think, though quite possibly watched) that they used quicksilver bearings for those lenses to turn and that those bearings would be cleaned out, possibly by hand, by the keeper.

I suppose that was before humans had what little respect for heavy metals they do today, but still... A bloody open-air quicksilver bearing!

(I must admit to not yet having watched the video - perhaps it is addressed therein?)

That's right, and they obtained the mercury from Hg Wells.
Title: Re: Fresnel lenses and Lighthouses
Post by: Dark Lightning on December 05, 2023, 12:45:41 AM
 :rofl:
Title: Re: Fresnel lenses and Lighthouses
Post by: Icarus on December 05, 2023, 01:12:01 AM
When I was a kid, eons ago, golf balls had a center filled with mercury.  An old golf ball was considered a prize by we kids. We would cut it open to get to the mercury and then be fascinated about the way it behaved in our bare hounds, or on a flat surface.

Title: Re: Fresnel lenses and Lighthouses
Post by: Asmodean on December 05, 2023, 02:02:43 PM
Quote from: hermes2015 on December 05, 2023, 12:19:08 AMThat's right, and they obtained the mercury from Hg Wells.
:rimshot:

The Asmo greatly approves of what you did right there.

Also, when I was young, I too was fascinated by quicksilver being all liquidy, yet forming perfect little balls in small quantities. Such was to be examined very closely, indeed. Preferably breathed in, if that could be arranged at all. I suppose I knew better, but... Still kicking, and not that mentally unhinged, so no harm, I suppose.
Title: Re: Fresnel lenses and Lighthouses
Post by: Tank on December 06, 2023, 09:16:58 AM
Quote from: hermes2015 on December 05, 2023, 12:19:08 AM...

That's right, and they obtained the mercury from Hg Wells.

:fingertap:  :fingertap:
Title: Re: Fresnel lenses and Lighthouses
Post by: Asmodean on December 08, 2023, 12:54:12 PM
:smilenod:

Hg wells. :smilenod:
Title: Re: Fresnel lenses and Lighthouses
Post by: hermes2015 on December 08, 2023, 04:10:11 PM
Quote from: Asmodean on December 08, 2023, 12:54:12 PM:smilenod:

Hg wells. :smilenod:

 :grin:
Title: Re: Fresnel lenses and Lighthouses
Post by: Recusant on December 08, 2023, 08:57:11 PM
Some might think cinnabarrasing sort of humor, but not I.   :couchhide: 
Title: Re: Fresnel lenses and Lighthouses
Post by: Tank on December 09, 2023, 12:13:10 PM
You just had to stick your oar in there didn't you  :foottap:
Title: Re: Fresnel lenses and Lighthouses
Post by: hermes2015 on December 09, 2023, 04:07:41 PM
Quote from: Recusant on December 08, 2023, 08:57:11 PMSome might think cinnabarrasing sort of humor, but not I.   :couchhide: 

Ha, in your element as usual.
Title: Re: Fresnel lenses and Lighthouses
Post by: Recusant on December 09, 2023, 04:49:46 PM
 :mustache: