Terry Clock Co. "Luminous Dial"

George Pins

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What do these words mean on the dial of an 1880's Terry Clock Co. shelf clock? Seems years too early for radium and the wristwatch tragic results.
 

George Pins

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Novicetimekeeper - Thanks for response, but your answer doesn't jibe with the date of this clock. Terry Clock Co. is gone in 1888, and even if we suppose that successor Russell & Jones used up inventory marked for Terry, R&J is gone by 1893.
 

novicetimekeeper

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Novicetimekeeper - Thanks for response, but your answer doesn't jibe with the date of this clock. Terry Clock Co. is gone in 1888, and even if we suppose that successor Russell & Jones used up inventory marked for Terry, R&J is gone by 1893.
I was just confirming what you thought, it doesn't mean radium.
 

Raymond Rice

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I have a Terry shelf clock with "Luminous" on the the dial. I had to test it with my trusty Geiger Counter --and nope, not radium. I suspect that the term "Luminous" was simply an advertising phrase.
Ray Rice
 

Uhralt

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Maybe it was the name of the model?

Uhralt
 

D.th.munroe

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I think it may have had something to do with just how white the paper dials were? They were advertised as shining all night long. But yes before radium being discovered (1898) and the patent dates I've seen on these "luminous" is Sept. 26, 1882, March 30, 1883. I'm still trying to find the actual patents.
 

Steven Thornberry

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I think it may have had something to do with just how white the paper dials were? They were advertised as shining all night long. But yes before radium being discovered (1898) and the patent dates I've seen on these "luminous" is Sept. 26, 1882, March 30, 1883. I'm still trying to find the actual patents.
The term "luminous" may refer to some sort of electrical illumination.

The latter patent date should be March 20, 1883. Below is a page showing several patents for "electric clocks" granted on that date.
https://pocketwatchdatabase.com/ref...turer=&q=&month=3&yearStart=1883&yearEnd=1883

I've found nothing for September 26, 1882.
 

George Pins

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With the clues furnished by those who have responded to my original post, I may have answered my own question. I found a patent issued September 26, 1882, #264,918, for "self-luminous paint." At page 1059 of the Patent Gazette. No formula given, just described as a phosphorescent material that is mixed with paint ingredients. Another patent issued March 20, 1883, #274,415, is for "luminous paper." At page 1109 of the Patent Gazette. A chemical formula is given (way above my chemistry pay grade, but not including radium) to treat paper to make it luminous. Combining the two patents, I think we have the answer.
 

Steven Thornberry

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With the clues furnished by those who have responded to my original post, I may have answered my own question. I found a patent issued September 26, 1882, #264,918, for "self-luminous paint." At page 1059 of the Patent Gazette. No formula given, just described as a phosphorescent material that is mixed with paint ingredients. Another patent issued March 20, 1883, #274,415, is for "luminous paper." At page 1109 of the Patent Gazette. A chemical formula is given (way above my chemistry pay grade, but not including radium) to treat paper to make it luminous. Combining the two patents, I think we have the answer.
Glad you found them. They are much more satisfactory than the electrical connections, as it were.
 

novicetimekeeper

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I guess this must be photoluminescence as is currently used on most wrist watches
 

JTD

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I guess this must be photoluminescence as is currently used on most wrist watches
I don't think so. As far as I can see neither patent would have been very successful. After the undesirable properties of radium came to light, tritium, which is much safer, was used instead. Nowadays I believe the lume used on watches is based on strontium aluminate.

JTD
 
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JTD

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With the clues furnished by those who have responded to my original post, I may have answered my own question. I found a patent issued September 26, 1882, #264,918, for "self-luminous paint." At page 1059 of the Patent Gazette. No formula given, just described as a phosphorescent material that is mixed with paint ingredients. Another patent issued March 20, 1883, #274,415, is for "luminous paper." At page 1109 of the Patent Gazette. A chemical formula is given (way above my chemistry pay grade, but not including radium) to treat paper to make it luminous. Combining the two patents, I think we have the answer.
Although I have only basic knowledge of chemistry, having looked at these patents I very much doubt if either method was very successful. Perhaps that is why we don't hear much about them.

JTD
 

novicetimekeeper

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I don't think so. As far as I can see neither patent would have been very successful. After the undesirable properties of radium came to light, tritium, which is much safer, was used instead. Nowadays I believe the lume used on watches is based on strontium aluminate.

JTD
Radium paint and Tritium, (used in gas filled tubes or combined in a paint) are both radioluminescents. Strontium aluminate is a photoluminescent material. Apart from those using tritium in gas filled capillaries I think all luminescence is now photo luminescence.
 

JTD

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I guess this must be photoluminescence as is currently used on most wrist watches
Radium paint and Tritium, (used in gas filled tubes or combined in a paint) are both radioluminescents. Strontium aluminate is a photoluminescent material. Apart from those using tritium in gas filled capillaries I think all luminescence is now photo luminescence.
I see what you what you were saying now, but it wasn't clear (to me) from the first post.

JTD
 

Uhralt

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When you read the patent you will find that the "luminescence" it is actually phosphorescence. This means the material needs to be exposed to light, gets into a energy rich excited stage and uses the energy slowly emitting light over an extended period of time after the excitation.

Uhralt
 

novicetimekeeper

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When you read the patent you will find that the "luminescence" it is actually phosphorescence. This means the material needs to be exposed to light, gets into a energy rich excited stage and uses the energy slowly emitting light over an extended period of time after the excitation.

Uhralt
Phosphorescence is a type of photoluminscence. The point being that the material does not fluoresce as a result of ionising radiation but though absorbing lower energy EM radiation. (UV is technically ionising radiation but doesn't count :) )The material remits as visible light over a period rather than immediately. Modern lumes have developed to extend the period during which the emission will take place.
 

George Pins

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novicetimekeeper - So if I understand you correctly, if this system worked initially, it still had a limited life. What would you guess? A year? Ten years? More? Insufficient information as to what was actually done?
 

novicetimekeeper

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I don't know about a limited life, if the compound is unstable it could change to something that does not have the property but it isn't like radium paint where the zinc sulphide is being affected by the radiation.
 
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