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BULB DISCUSSION BOARDS => Antique Bulb Discussion => Topic started by: glendaer on November 17, 2001, 09:27:00 pm

Title: Patent 1904 Mazda
Post by: glendaer on November 17, 2001, 09:27:00 pm

The light bulb I have has the following markings:
National Mazda and the GE symbol on the bulb.
PAT. NOV 8 1904 on the base.
25a2  7UD hand written on the inside piece of glass (Note: the "a" is either a lower case "a" or a funny looking "w").
I have 2 questions.
- What does the 25a2  7UD mean?
- According to your timeline, the Mazda came out in 1909.  Can you tell me why my bulb says 1904?

Thanks,
Glenda

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Glenda

Title: Patent 1904 Mazda
Post by: Ed Covington on November 18, 2001, 12:59:00 pm

Glenda, I hope the following is of some help. Ink codes on the glass stems are generally quite confusing. Each factory seemed to have its own way of marking. However, within National standardizing started about 1912 and in some cases it is possible to determine lamp watts, voltages, lamp factory and date of manufacture. In your case the following is what I believe to be true: The "25" refers to lamp watts. The "a2" is the lamp voltage, which,in your case, is 112 volts. The "7UD" probably gives the factory I.D.; I don't know how to interpret that code. At one time the number "7" referred to a factory in Oakland, CA but I wouldn't want to make that assumption about your lamp. The date "Nov 8, 1904" probably refers to the date a patent was granted to Alfred Swan (brother of Sir Joseph W. Swan) for the design of the base. That patent covered the use of the black glass insulator between the brass parts. The insulator prior to the black glass was porcelain. I would guess that your lamp was manufactured about 1913-1915.

Title: Patent 1904 Mazda
Post by: glendaer on November 19, 2001, 08:15:00 pm

Thank you for your quick and thorough response! I find new discoveries in my new/old (1870) home every day and like to know the history behind these items.

Title: Patent 1904 Mazda
Post by: Tim on January 17, 2002, 11:15:00 am

Ed,

Do you have any information concerning the "1907" patent mark that appears on the base of some skirted base lamps?  The mark appears as: Pat. Oct. 15 1907

I suspect it may be the design for this type of base but I do not have any proof.  If anyone knows the patent number that covers this I would be interested in knowing this.

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Tim
Kilokat's Antique Light Bulb Site (http://www.bulbcollector.com)
Mountain Dew Collectibles, Volume I (http://www.dewcollector.com)

Title: Patent 1904 Mazda
Post by: Bob Masters on January 17, 2002, 11:41:00 am

Glenda,

WOW ! You found that bulb in your home ?
How did you come across it ?

-Bob-

Title: Patent 1904 Mazda
Post by: Ed Covington on January 17, 2002, 10:16:00 pm

Tim, I don't know what was patented on Oct 15, 1907 but I can look it up for you if you're interested. I'm going to Cleveland next month and would be happy to get the answer.

Title: Patent 1904 Mazda
Post by: Tim on January 19, 2002, 12:10:00 am

Thanks for any info you can provide Ed, I do appreciate it.  BTW, here's a picture of the bulb in question.  It's an early pressed tungsten filament lamp.  Unfortunately the filament is blown but I assume not too many early examples survived?

(http://www.bulbcollector.com/photos/Tungsten_1907.jpg)

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Tim
Kilokat's Antique Light Bulb Site (http://www.bulbcollector.com)
Mountain Dew Collectibles, Volume I (http://www.dewcollector.com)