Bubble Lights

The history behind the lights…

The story of the Christmas bubbling light is an interesting one, and begins with NOMA Electric Corporation’s purchase of exclusive patent licenses from Carl Otis, the holder of a patent for bubbling lights. Bubble Lites became NOMA’S best sellers, and the battle soon began…

On November 27, 1935, Carl Otis filed a patent application for what was simply called “Display”, a bubbling table top sign and the first of several patents he was to hold. It was granted on September 26, 1939 and was assigned #2,174,446. This patent was to become the basis of his new idea: small, bubbling lights specifically adapted for use on Christmas trees.

Carl’s idea was not new-in fact, sealed glass tubes with a bubbling liquid inside were first demonstrated by Benjamin Franklin. Several earlier patents were granted for bubbling signs, the first of which to Raffaele Floravanti on February 18, 1936 (#2,031,409), and another to Alfonse Kaufman on that same date (#2,031,416). Also, a patent for a bubbling sign employing different colored tubes was granted on June 20, 1939 to Philip Rosenblatt as number 2,162,897. Each of these patents, though similar in many respects, were apparently dissimilar enough for each to be considered “new” by the United States Patent and Trademark Office.

Here are the four pages of the original patent granted to Carl Otis for his sign:

One of the major differences between Carl’s sign and the others was the method he employed to evenly distribute and generate bubbles. He used a porous wooden plug, permanently wedged in the bottom of the tube. This plug served to form many small chambers of the bubbling chemical, which effectively spread it out thinly and close to the heat source, allowing for a much faster boiling time. This particular feature was to become a major factor in later legal developments with regard to the validity of Mr. Otis’ patents.

1940s Wurlitzer Bubbling Sign 1940s Wurlitzer Bubbling Sign


Even before the above patent was granted, Carl was working on his concept for the Christmas tree bubble light, which he called an “Ornamental Illuminating Device .” His second patent application was filed in early November of 1941, and was finally granted on July 4, 1944 as #2,353,Bubble Light First Patent.jpg (82592 bytes)063. Even before the patent was granted, he sent out sample tubes to 10 of the biggest Christmas light companies then in business, demonstrating how they could be incorporated in Christmas lights. Only one company, NOMA Electric, showed any interest. This patent, pictured at the right, plainly shows the now familiar style of NOMA’s famous bubblers. Note that instead of using a wooden plug wedged in the bottom of the tube, a loose glass plug was substituted. Slightly concave on its underside, this plug held a small chamber of the bubbling liquid, methylene chloride, thinly and closely to the heat source, just as the wooden plug in the previous patent did. The glass plug better allowed light to penetrate the tube. Also note that the light bulb picture in the patent drawing has a rounded top, whereas the lamps produced after the first couple of years incorporated a flat top to facilitate better heat transfer. The rights to this patent, as well as Mr. Otis’ previous one, were both purchased by the NOMA Electric Corporation, and Carl Otis was hired by them to further develop the bubbling lights.

A third patent for an “Ornamental Illuminating Device” was applied for by Mr. Otis on January 28, 1942 and granted as patent number 2,383,941 on September 4, 1945. Although quite similar to his previous efforts, it contains one important difference: a mass of bonded chemicals or glass beads was fixed to the bottom of the bubble tube instead of the glass slug utilized in the previous patents. This mass served the same purpose as its predecessors-to hold small chambers of fluid close to the heat source to start the bubbling action quickly. Collectors today can find examples of both types of “bubble generators” in their NOMA tubes-the glass plugs and the chemical blobs. Due to the effects of time, most of the chemical blobs are now loose, and float around freely in the bubbling liquid. Originally, they were firmly affixed to the bottom of the bubble tubes. Carl noted in this last patent that the glass slugs produced an audible rattling noise when the lights were bubbling, and today examples of the slug-type of bubblers can be heard tinkling away happily on the branches of the family Christmas tree.

The onset of World War II prevented NOMA from introducing their lights until its conclusion, due to both wartime restrictions and materials shortages. The actual introduction date of the bubble lights is a bit of controversy, and Bubble Light there are collectors who claim either 1945 or 1946 as the first year of commercial sale. There are valid arguments for either year, and I personally do not have enough information to offer my own opinion. There is even a bit of speculation that a few experimental bubble lights were sold as early as the fall of 1942. At any rate, the very first NOMA biscuit style bubble lights can be easily identified, as the biscuit halves are held together by small metal clips attached at the ventilation holes (see the picture immediately to the right). This method of attachment is not referred to in any of the patent drawings, and apparently was used for only a very short time. They are extremely hard for collectors to find. Another clue to an early bubble light is the name “Matchless” on the bottom of the lamp, referring to the manufacturer of the light bulbs used in the base. Refer to the next page in this section for more details about the early production NOMA bubblers.

In 1946, NOMA sold their bubble lites in the box pictured here, referred to as a “Book style” container by collectors. The inner flap had a colorful picture of a little girl smiling happily while staring at the operating bubble lites. These lights were HUGE sellers, and rapidly became the most popular Christmas lights NOMA had ever sold. NOMA purchased the rights to Carl Otis’ latest patent, and he agreed to a royalty payment of 3 cents for each light produced. Considering that NOMA made more than 25 million bubble lites in the first two years of production, Carl’s royalty payment was to be quite a sum!

The other Christmas light manufacturers were watching the sales of NOMA’s new product with great interest, and almost immediately began manufacturing their own versions of the popular light. Raylite, the second largest Christmas light manufacturer and maker of Paramount products, started selling their own bubblers almost immediately, calling them Kristal Snow Animated Candles. NOMA was not amused, and promptly sent them a warning letter of infringement, claiming that since they were the exclusive licensee of all three of Carl Otis’ patents, Raylite was infringing . Raylite responded with claims asserting that Carl’s patents were invalid. They filed court papers attempting to stop NOMA from further patent infringement claims against them. The battle lines had been drawn, and poor Carl Otis was stuck right in the middle of the mess.

1948 Paramount Kristal Snow Animated Candles A look inside the box at these exceeding rare lamps

The subsequent court cases were quite complex, and I have only small bits of the court records to reference. It was a nasty fight, with representatives from both companies defending their positions quite aggressively. At one point, a temporary halt was put to the proceedings when Raylite steadfastly refused to provide NOMA with a sample of their bubble light for examination. Raylite claimed that they had only one sample, and would not part with it or allow it to be taken apart by NOMA representatives. NOMA filed a motion for a further “Bill of Particulars”, asserting that they could not properly prove infringement unless they could demonstrate and compare Raylite’s product against their own. Raylite claimed that they had only one sample, as the product had not yet been put into production. NOMA claimed that Raylite had “demonstrated their light to the trade”, and therefore samples must be available. The presiding judge ordered Raylite to provide a sample, which they still refused to do. A judgment was entered in NOMA’s favor, granting drawings, samples and all pertinent information so as to allow NOMA the ability to compare the Raylite product against their own. The court order was dated December 23, 1946.

While all of this was going on, a few of the Christmas lighting companies, including Raylite, offered NOMA a royalty of three cents for each light they produced. NOMA offered to split this three cents with Mr. Otis, but he refused. It was at this point that he became directly involved in the court cases, and intervened as a defendant. The District Court for the Southern District of New York rendered a judgment invalidating parts of Carl’s patents, and he promptly appealed. The case suddenly became even more complicated.

As the proceedings dragged on, NOMA and Raylite agreed to drop their fight involving two of the patents, numbers 2,174,446 and 2,353,063 when it became clear that the court was sure to invalidate them. NOMA then promptly cancelled its license with Carl for both. Carl appealed this action and lost. Everything was now hinging on the validity of his sole remaining patent, number 2,383,941.

The crux of this patent was Carl’s assertion that he had invented a new method for assuring that the bubbling action in the glass tube of the lights would be reliable, fast starting, and even. This was accomplished, he claimed, by either of the two methods covered in his last patent-the glass slug or the porous chemical mass fixed at the bottom of the tube. Carl testified that without either of these devices, the methylene chloride would either circulate within the tube and thereby fail to reach a boiling point, or produce an action known as “bumping”, which is the accumulation and subsequent sudden release of a large mass of bubbles in an uneven and unattractive cycle. He claimed that his methods of isolating a small amount of liquid, bringing it rapidly to a boiling point and then controlling its release were unique and heretofore not previously addressed, anticipated or patented.

Raylite moved swiftly, presenting an earlier patent by Phillip Rosenblatt, number 2,278,383 that was granted on March 31, 1942, well before Carl Otis’ patent of September 4, 1945. Rosenblatt’s patent was for a “Display Device”, and is pictured on the left. The specifics of this patent for a bubbling display address the “bumping” issue, and in fact the invention was presented precisely as a solution to that problem. His apparatus incorporated a wad of glass wool in the bottom of the fluid container and adjacent to the heat source, the effect of which assured even production and distribution of appropriately sized bubbles. Rosenblatt even went so far as to say that while glass wool was a preferred substance, materials like shot or glass beads could be used, both of which were mentioned in Carl’s patent.

Carl argued that the specifics of Rosenblatt’s patent included reference to a large bubble formed within the glass wool fibers, almost completely enclosing it. The outside liquid then enters the vapor space of the bubble, and is in turn vaporized itself, breaking away and forming a stream of bubbles. He related that his patent made no mention of a large, entrapped bubble, but relied on a process he called “superheating.” The action in his bubbling tubes, he claimed, was far different than that in Rosenblatt’s device.

The court disagreed. It felt that the process was essentially the same in both devices, whereby a small amount of liquid chemical is held close to a heat source, essentially apart from the main body of fluid. The court saw little difference in the effects of Rosenblatt’s glass wool, or Otis’ hardened and porous chemical mass. Poor Carl Otis’ last remaining patent was invalidated, and the court found it therefore unnecessary to determine any infringement on the part of Raylite. NOMA immediately terminated its licensing agreement with Otis, and although he appealed both the license termination and the court case, he lost. The final judgment against him was affirmed by the United States Court of Appeals, Second Circuit on February 2, 1950. The case had dragged on for almost four years. The final association agreement between Carl Otis and NOMA was terminated, and Carl received no further royalty payments from any Christmas lighting company.

Had Mr. Otis approached his patent from a different angle, one of the miniaturization of bubbling devices, perhaps the outcome of the court case would have been different. But the courts held that he had in actuality invented nothing, and Carl was the biggest loser, in effect receiving nothing for his invention. Raylite was a huge winner, as it was now free to market bubble lights as it saw fit. There is no evidence that NOMA ever entered into negotiations with Rosenblatt for the license to his patent, and they were now free to continue manufacture of their lights without any royalty payments to Carl Otis. Although they lost exclusive rights to the manufacture of bubbling lights, they had been first, and the NOMA name was well known. Millions upon millions of their bubbling lights would continue to be made up until the mid 1960s, and NOMA lights were always the best sellers of any of the various styles of bubbling lights. Literally hundreds of thousands of those original lights remain in use today, still bubbling away, just as they first did during the 1940s.

The amazing bubble lights were THE lights to have during the end of the 1940s. Millions upon millions of them were made. The history of their invention is an interesting story-and a complicated one as well.

Bubble NOMA 1949 UL outside

Outside Inner Flap Contents Close up
of Bubble Lite

In 1946, NOMA first marketed their soon-to-be-famous famous Bubble Lites in the book-type box pictured above. Consisting of a glass tube filled with  methylene chloride and a plastic base that holds a light bulb in close contact with the tube, the units bubble merrily whenever heated. The chemical has such a low boiling point that it will even bubble from the heat of your hand or the sunlight entering through a window. The liquid in the tubes comes tinted in several colors, with purple being the rarest as it was only sold for the first three years of production. As shown in the close-up picture on the left, the earliest bubble lights have glass slugs within the tubes, to help activate and spread out the bubbles. Soon it was discovered that the slugs were not really needed, and after 1949 they were no longer used. Lights without the glass tubes, however, do tend to have larger and unevenly produced bubbles. Bubble Lites quickly became the best selling and most profitable Christmas lights of their day.

Prototype NOMA Bubble Lite.
These were sold in very
limited quantities during the first year
of full production in 1946.

Standard production
NOMA Bubble Lite, sold
from 1946 to 1963.

Although not shown in the patent drawings, the NOMA biscuit style bubble light was originally intended to have an easily replaceable bulb. The top and bottom halves of the light were held together with metal clips, which allowed for disassembly. The bottom half of the biscuit which contained the lamp was actually made by The Matchless Electric Company, maker of the famous Matchless Stars. It is made of a very different plastic than NOMA used for the top half of the light. You’ll easily be able to spot the difference-the Matchless plastic has a satin finish, while the NOMA plastic is quite shiny. Midway into the first year of [production, NOMA switched to using their own plastics, General Electric flat topped bulbs, and glued the base halves together instead of clipping them.

By 1947, NOMA’s Bubble Lites were THE thing to have for a properly decorated tree. Wisely, NOMA offered boxes of replacement lamps for existing light strings, advertising them a replacements for the “old style Christmas light” and as “bubbling lights of incredible beauty”. The box pictured above was meant to be sold as a complete set of 10 lamps, but often shopkeepers would put a box on a countertop and sell the lights individually for 15 to 25 cents each. Collectors call these lights “biscuits”, due to the style of the base.

In 1948, NOMA chose to change the style of their bubblers, perhaps in an attempt to “modernize” them a bit, or it may have been to differentiate the shape from all of the NOMA competitors who shamelessly used similar “biscuit” base styles. Whatever the reason, NOMA decided on the saucer shape as pictured on the left. This design was extremely susceptible to heat damage due to the more confined space for the light bulb, and was discontinued once stock sold through in 1949. Most examples of this style of light show at least some warping from heat stress. All NOMA advertising showing the little boy with the Santa beard is 1948 or later. The image on the right is the replacement lights box, from the 1948 NOMA catalog. Once the biscuit style of bubble light resumed production, the previously discussed glass slug in the tube was no longer used.

Beginning in 1948, NOMA marketed a multiple wired bubble light outfit as shown here.Notice that the top part of the base of these lights uses the “saucer” from the series wired set above. Anticipating huge sales for the 1948 Christmas season, NOMA produced vast quantities of these saucers only to find out that they were not suitable for the series outfits. Stuck with a large inventory of saucer halves, the Company was quite inventive in using them all the way through the 1960s.

1949 and 1950 were pivotal years for NOMA. Shortly after their success with the Bubble Lites, other companies almost immediately issued their own versions of the popular lights. Some companies, like Paramount, circumvented the patents by using oil in their tubes while others blatantly challenged the patent by using the same methylene chloride that NOMA used. When the issue was finally settled in the courts in 1950, NOMA lost and the market was suddenly wide open for all. Sticking with their original success, NOMA reissued the famous “biscuit” style lights, in the slightly modernized box as pictured here. The little girl staring in wonderment at the bubbling light pictured on the earlier box of replacement bubble lites changed her dress from a early 40s style blue outfit with stripes to a much more timely solid green dress. Her eyes had also mysteriously changed color from blue to green to match her new outfit.

Adding to NOMA’s competition troubles in 1948, one of their sets of bubble lights was accused of starting a fire, which tragically involved a fatality. NOMA immediately added a fire retardant chemical to their plastic. NOMA outfits that include this chemical are clearly and boldly marked with the UL approval information on the front cover of the box.

The chemical caused the premature breakdown of the plastic in the lights, making them useless within a few years. Lights showing this disintegration are shrunken and severely distorted (fourth picture from left above), and are often found with a whitish coating that is erroneously attributed to spray snow or heat damage. Note that since these lights are from 1949 and later, they do not contain the glass slug. After a few years, it was determined that the NOMA bubble light set was not the cause of the fire, and the chemical was no longer used in the manufacture of the lights. The picture at the right above is of an ad NOMA strategically placed in the 1949 edition of Fire Engineering Magazine, explaining the use of the new chemical.