Lighting with longevity: The Centennial light bulb

-November 23, 2012

A few months ago I started writing this blog but got way behind and I am hoping I don’t procrastinate and it becomes the 111th year celebration of the Centennial Light Bulb on June 18, 2013. Suffering for a week without power due to hurricane Sandy acutely reminded me how great an invention the incandescent light bulb was for mankind.

As I researched stories about this amazing Shelby1 manufactured light bulb (Figure 1), I found many interesting facts about the technology in making light bulbs. As well as many interesting stories about the invention of the light bulb and the “Phoebus Cartel”2 that fixed the life of light bulbs to 1,000 hours.

Figure 1 "Live" Web Bulb Cam at the Livermore Fire Department Building

As it in turns out 110 years is 963,600 hours. So what keeps this light bulb glowing from June of 1901?

As shown in Figure 2 the carbon based filament is thicker and more robust than the tungsten filaments of today’s light bulb. A detailed analysis performed by Professor Debora M. Katz of Annapolis Physics Department is available at the Centennial Bulb Web site. 

“Thomas Edison’s first commercial bulb in 1881 lasted for 1,500 hours; soon, bulb-makers were proudly advertising 2,500-hour bulbs. But in 1924, the main bulb manufacturers in America and Europe secretly formed a cartel to limit the average life of lamps to 1,000 hours. By the 1940s, 1,000-hour bulbs became the standard. Eventually, the cartel2 was exposed, and in 1953, General Electric and other industry leaders were banned from limiting the light bulb’s life span.”3

In 1902 Adolphe A. Chaillet of the Shelby Electric Company, the inventor of the improved filament was issued a patent but no details of the filament construction and material were revealed.  

The invention of the light bulb has always been attributed to Thomas Edison. However, as shown in the time line of Figure 3 many inventors have contributed to improving the technology of manufacturing a practical incandescent light bulb. There still is no doubt that Edison did provide the first successful mass-produced incandescent lamp as well as his successor company General Electric.

Figure 2 Construction of Shelby Light Bulb

Figure 3 Timeline of the Invention of the Incandescent Light Bulb

“Incandescent light bulbs are gradually being replaced in many applications by other types of electric lights, such as fluorescent lamps, compact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diodes (LEDs) due to their inefficiency”4, the invention of the incandescent light bulbs still will always be remembered as one of the greatest inventions of all time.

Like the Kenny Rogers song  “They Don't Make Them Like They Used To”. Whether it is cars, appliance or electronics. Is there planned obsolescence?


  1. The Shelby Electric Company - Shelby, Ohio web site
  2. 2010 European documentary “The Light Bulb Conspiracy.”
  3. “Reign of Shine: Seeking Secrets behind the bulb” By Jeanine Benca, Mercury News, February 6, 2011
  4. Wikipedia “Incandescent Light Bulb”

Further links for reading

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