Author Topic: Railroad Lantern Globes  (Read 270 times)

Offline Duffy

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Railroad Lantern Globes
« on: November 23, 2017, 03:27:26 PM »
Picked these Railroad Lantern Globes up for $4.00 for all 5. 3 Corning and 2 Kopp's. The 3 corning has chips on them. The red Kopp is perfect and the orange Kopp has one small chip.
CDN Doug

Offline TelePlay

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Re: Railroad Lantern Globes
« Reply #1 on: November 23, 2017, 04:46:34 PM »
Picked these Railroad Lantern Globes up for $4.00 for all 5. 3 Corning and 2 Kopp's. The 3 corning has chips on them. The red Kopp is perfect and the orange Kopp has one small chip.

That was a deal.

Where are the chips, on the ground ends? Those are referred to as "flea bites" and don't affect the globe's value. Large chips cause cracks so if it is just chips, they are bites.

Those are $20 each plus shipping the the Lanternnet site.
            John . . .

              

Offline Duffy

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Re: Railroad Lantern Globes
« Reply #2 on: November 23, 2017, 06:44:28 PM »
Thanks John for the info,

Here is what I call chips and what I think you are calling Flea Bites.
CDN Doug

Offline Fabius

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Re: Railroad Lantern Globes
« Reply #3 on: November 23, 2017, 08:37:14 PM »
I think those are Fresnel globes.
Tom Vaughn
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Offline TelePlay

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Re: Railroad Lantern Globes
« Reply #4 on: November 23, 2017, 08:41:11 PM »
This is what I meant by flea bites. What you have are chips.
            John . . .

              

Offline Duffy

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Re: Railroad Lantern Globes
« Reply #5 on: November 23, 2017, 08:47:00 PM »
I think those are Fresnel globes.

I have no idea what that means, I know nothing about lanterns and their globes. I just happen to find them in a thrift store, I thought they were neat and just couldn't leave them there for $4.00.
CDN Doug

Offline Duffy

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Re: Railroad Lantern Globes
« Reply #6 on: November 23, 2017, 08:52:24 PM »
This is what I meant by flea bites. What you have are chips.

So are they still worth anything?
CDN Doug

Offline TelePlay

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Re: Railroad Lantern Globes
« Reply #7 on: November 23, 2017, 09:24:31 PM »
I have no idea what that means, I know nothing about lanterns and their globes. I just happen to find them in a thrift store, I thought they were neat and just couldn't leave them there for $4.00.

I'm going to defer to this from another site to basically describe a Fresnel lens:

"If you have ever looked at the lens of a magnifying glass, you know that it is thick in the middle and tapers down to nothing at the edges. In other words, it is shaped like a lentil, which is where the word lens comes from. It would not be very easy to make a big magnifying glass lens for your RV because it would be thick, heavy and hard to mount.

The thin piece of plastic you are using is called a Fresnel lens. It is flat on one side and ridged on the other. Fresnel lenses we first used in the 1800s as the lens that focuses the beam in lighthouse lamps. Plastic Fresnel lenses are used as magnifiers when a thin, light lens is needed. The quality of the image is not nearly as good as that from a continuous glass lens, but in lots of applications (like your RV), perfect image quality is not necessary.

The basic idea behind a Fresnel lens is simple. Imagine taking a plastic magnifying glass lens and slicing it into a hundred concentric rings (like the rings of a tree). Each ring is slightly thinner than the next and focuses the light toward the center. Now take each ring, modify it so that it's flat on one side, and make it the same thickness as the others. To retain the rings' ability to focus the light toward the center, the angle of each ring's angled face will be different. Now if you stack all the rings back together, you have a Fresnel lens. You can make the lens extremely large if you like. Large Fresnel lenses are often used as ­solar concentrators."


With those globes, it bends the light from the "ball" of fire on the wick to a horizontal beam to make the light brighter, focusing any light that touches the glass in one direction due to the ridges and the diffraction of the glass. Lighthouses have used very large variations of the highway torch globe and they were not cheap.

Your globes are worth something. Certainly more that you paid for them. Since the highway markers did not burn as hot as a lantern used to light up a room, the glass does not get as hot and as such, not hot enough to cause the chip to turn into a crack, hopefully. I've not had one of these so any member who has a traffic market lamp can say how hot the glass gets in use.

This is a complex first-order lighthouse Fresnel lens on display at the Point Arena Lighthouse Museum, Point Arena Lighthouse, Mendocino County, California.

            John . . .

              

Offline Duffy

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Re: Railroad Lantern Globes
« Reply #8 on: November 23, 2017, 09:34:29 PM »
Thanks John,

I learned something new today.  ;)
CDN Doug

Offline RB

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Re: Railroad Lantern Globes
« Reply #9 on: November 30, 2017, 11:40:30 AM »
Those are the same type of lenz used on the first projection tv's

Offline AL_as_needed

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Re: Railroad Lantern Globes
« Reply #10 on: December 17, 2017, 08:38:18 AM »
Would almost be tempted to say those would work in my Dietz # 40 Traffic Guard, which uses a red fresnel lens with a small "sight glass" for wick adjustment.

http://www.classicrotaryphones.com/forum/index.php?topic=18759.msg192907#msg192907
TWinbrook7