A Brief History of Christmas Tree Lighting

Christmas trees have been lit by one technology or another as long as we have records. For centuries, they were lit with candles, usually in little holders that clipped to the branches. Of course they were dangerous, but in most households before about 1870, the trees were "table-top" trees that were only 3' or so tall, and they were only lit (or even displayed) on Christmas Eve and Christmas morning. As the trees got larger, and the time for displaying them got longer, the risk posed by using lit candles increased.

A few folks experimented with electric lighting for their trees, but commercial products were not widely available until about 1903.

Electric light strands were originally called "festoons," used round or pear-shaped bulbs, and cost two weeks' wages for most sets. Between 1903 and 1920, they became more standard and the price dropped to an amount many families could afford.

C6 Bulbs Some readers may remember C6 bulbs. These usually came eight to a strand. They were wired in a series so if one burned out, the whole strand went dark. They also got hot enough to set fire to almost anything combustible if they were left in contact long enough. And the paint scratched easily off of the bulb, so pinpoints of glaring white light often overwhelmed the paint color on bulbs that had been used more than two or three seasons. That said, they were still safer than candles as long as they weren't left unattended on a dry tree.

Note: Collectors and brothers Bill and George Nelson once charted the development of the early Christmas lights in a web article that is now being restored as part of the attempt to keep their findings available for future generations.

As an interesting aside, the cardboard Christmas village houses popular in the 1930s-1960s almost always came in sets of eight, so you could use them with early C6 sets. (For more information about those cardboard houses, check out the Big Indoor Trains Primer article "About Glitterhouses.")

C7 Bulbs - C6 bulbs were eventually replaced by C7 bulbs, the same kind of screw-in bulbs that are still used in night lights and electric "candles" today. Each bulb is actually 110 volt, so C7 bulbs don't depend on series wiring to step down the voltage. This allows them to be wired in parallel. If one light goes out, the rest really do stay lit. At first most C7 bulbs used a ceramic finish which resisted scratching better than the paint on the C6 bulbs. Ceramic-finished C7 bulbs still got hot, but the sockets had little clips so you could position the bulb away from needles and other branches. After a few years, a "clear, tinted glass" was used on some C7 bulbs. These stayed relatively cool, and were much safer in general on a cut tree.

One variant of C7 bulbs that I especially liked was the "twinkle" light. Not to be confused with today's "twinkle" lights (most of which don't actually twinkle unless you set the whole strand to go on and off), these had little thermostats inside each bulb which caused them to turn off and on every so often. Each thermostat was a little different, so the effect was totally random, a sort of light show that could be almost as hypnoptic to watch as a fire or a train circling the tree, especially when music was playing. Although C7 twinkle lights used tinted glass instead of a ceramic finish, when they were on, they got almost as hot as the ceramic finish bulbs - that was part of the technology.

If you use C7 bulbs of any kind, try to mount them so that no needles are laying up against the bulb (this is important for an artifical tree but critical for a real tree).

C9 Bulbs - When people wanted to use Christmas-tree style lighting outdoors, they found that the C7 bulbs didn't show up all that well, and the strands weren't made to resist water. A slightly larger format, C9, was adapted to resist water infiltration from rain and snow. C9s are seldom used on indoor Christmas Trees, but for decades, they were used on many outdoor displays including live trees being lit for Christmas. They are still used to some extent today. Almost all C9s have a ceramic finish and get very warm. On the other hand, a living outdoor tree standing in a cold wind can handle quite a bit more heat before it ignites than a dried-out cut tree indoors, so C9s are not considered a huge risk when used properly.

What do C6, C7, and C9 Mean? The ratings C6, C7, and C9 actually refer to the size of the glass part of the bulb, not the voltage, wattage, or size of the base, so someone MAY come along with an LED bulb that they call a C9, but which is only visually compatible with traditional incandescent C9 bulbs, while having an entirely different socket type and requiring an entirely different kind of electric current.

That said, traditional incandescent Christmas lights that are designated C6, C7, or C9 follow these standards:

If you're in the Christmas lights section and you see incandescent lamps with screw-in bases labeled C7 or C9, it's pretty safe to assume that they will work in the C7 or C9 light set you have at home. However, you can't make that assumption with LED sets, which may just be called C7 because the plastic "bulb" part of the light is the same size as the traditional incandescent C7.

Miniature Bulb Sets - By the late 1960s, series lights were making a comeback. The new ones used much smaller bulbs that popped into tiny sockets and came in strands of 25 or 50 (and eventually more). The advertising and packaging for these sets has always promised that if one light "goes out" the rest of the strand stays lit. "Goes out" means that the lamp burns out in a way that allows what is left of the filament to continue conducting electricity, a design feature of miniature bulbs. The advertising and packaging doesn't address what happens if two lights "go out" or if one lamp's filament is vaporized or if lamps become loose in their sockets so that you can only get the strand to light by "jiggling" it. In the days of C6 bulbs, you might have to unscrew and screw in up to 9 bulbs to figure out which one has caused the strand to stop working. The average miniature light set today has 50 bulbs in a series (larger sets are usually subdivided into multiple 50-bulb series). If you can't tell visually which bulb has caused the rest of the strand to go out, you have a lot of "plug-and-playing" ahead of you to fix the strand, and there are no guarantees, even if you replace very bulb one at a time.

Unfortunately for the planet, but fortunately for miniature bulb set manufacturers, by the late 1970s, many Americans had got into a "binge-and-purge" mentality about Christmas decorations anyway, buying new lights for the tree every year, so they seldom owned a strand long enough to experience problems with it. In fact, some manufacturers make a point of changing the shape of the sockets every few years, so you can't use bulbs from an old set to "fix" a newer set one - and you thought "planned obsolence" was reserved for the automotive industry. (As a person who recycles when reasonably able, I can't help but think sadly of all the copper that is now in landfills due this mentality and these marketing practices.)

New and Improved Miniature Bulb Sets - Since they were introduced, many variations and a few improvements have been offered.

• Different shapes - Target Stores especially has often offered mini bulb sets in different shapes, such as teardrop shapes, "button," or "pearl" bulbs. These are very useful for "special-purpose" trees or one-of-a-kind Christmas displays.

• More robust technology - Phillips is now advertising a set that will supposedly stay lit even if a bulb burns out, comes loose, falls out, or is broken. If this claim is true, it will remove the last serious hassle of using miniature light sets. Unfortunately, I've had "uneven" experience with other Phillips' household light bulbs, so the advertising alone hasn't convinced me. In January of 2009, I bought a few strands for 75% off, so I'll report on them later.

In the meantime, I just came across a C7 light strand that I bought in the early 1970s and it still works great, a HUGE contrast with the light sets being made today.

LED Light Strands - All of the lights we have discussed so far are incandescent, which means that they glow because electricity makes a tungsten filamant inside the bulb white-hot. Beginning about 2006, strands that use another technology began to appear. I would not be surprised if they replace most incandescent lighting strands within a few years.

Light-Emitting-Diodes have been around for over half a century. They are a solid-state device that produce light when a low-voltage DC current is fed through them in the right direction. Virtually no heat is generated and relatively little electricity is consumed. At first only a few colors were available, but today, most colors are possible. As the uses for LEDs have multiplied (including calculators, Jumbotrons, and even home lighting), newer applications are constantly appearing.

In the early 1980s, I toyed (unsuccessfully) with trying to get a bunch of little LEDs to light a miniature Christmas tree, but it took another twenty years before companies started investigating them as a serious alternative to incandescent Christmas tree lights.

In 2008, most LED Christmas light strands I saw had "bulbs" that are the size of, say, pencil erasers. (Other sized "bulbs" were bigger and different shapes, but not particularly brighter.) The most popular colors in 2008 were "white" (really a bluish white), "blue," and "multi-colored." In January, 2009 clearance sales, I bought a strand of "multi" and several strands each of blue and white to experiment with next holiday season, both trees and on my garden railroad's open house display (which uses far more lights than our trees).

One disadvantage of 2008's "white" LEDs is that their bluish tint makes them look quite distinct from similar-format incandescent lights (which have a golden tint when seen from a ways back). So you can't mix and match them on the same tree or in closely adjacent displays. And they may look "funny" to people until folks start getting used to them. (Note: Some suppliers are listing "warm white" lights which are supposed to be closer to the traditional incandescent hue.)

The colored LED strands have relatively rich colors, though, so they provide a nice effect when used as you might use miniature incandescent strands. A few sets have larger "bulbs" that are globe-shaped or which imitate the appearance of C7 or C9 bulbs.

The advantages of LED Christmas light strands significantly outweigh the advantages of incandescent strands (or at least they will, whenever the price starts becoming more equitable).

• LEDs have a much longer life than incandescents. The jury is still out on HOW much longer, since this kind of strand hasn't been around long enough to start burning out yet, but for most people an LED strand should probably last at least five times as long as a similar incandescent strand (if not longer). (If you're dead set on throwing your lights away at the end of each Christmas season, this doesn't apply to you, obviously.)
• LEDs require much less electricity than incandescents, often about 10% as much power. That means that if you do the "Clark Griswold" and your outdoor lighting has been costing you $2000 each December, it could go as low as $200 a month, not a bad exchange for laying out 2-4X the money up front per strand.

A Note About Prelit Trees

Again, Phillips is now advertising pre-lit trees on which the strands supposedly stay lit even if a bulb burns out, comes loose, or is broken. Pre-lit trees using LEDs (even more reliable) are starting to emerge.

In the meantime, I like the flexibility and maintainability of having separate lights, even if it's a little more hassle each year.

Conclusion

In the meantime, I hope you enjoy visiting our site and checking out other ideas for commemorating Christmas and your own family's traditions.

We are especially hoping that this article helps you have a happy and safe holiday season.

Please contact us with any questions, corrections, additions, or other suggestions.

And have a great family Christmas,

Paul and Shelia Race

www.familychristmasonline.com

Editor's Note: The Internet's best and most complete resource on the history of Christmas tree lighting has been restored and is now available at OldChristmasTreeLights.com The photos and history compiled between 1999 and 2008 by collectors and brothers Bill and George Nelson have been valued by collectors worldwide. When the last version of the site went down in early 2010, we went on a sort of digital scavenger hunt to restore and piece together as much information as we possibly could, in an effort to keep the brothers' findings available for future generations. Click on the picture to the right to visit the restored site.