Bubble Lights

I just love Bubble Lights. I still stare at them in amazement, just like I did on my grandmothers tree. 

How do they bubble?

A bubble light is a decorative device consisting of a liquid-filled vial that is heated and lighted by an incandescent light bulb. Because of the liquid's low boiling point, the modest heat generated by the lamp causes the liquid to boil and bubble up from the vial's base. The liquid is almost always methylene chloride, but some early bubble lights used a lightweight oil. The light from the lamp illuminates the bubbles from underneath, causing them to shine.

-provided by Wikipedia

Where did they come from? 

In 1935, Carl Otis filed a patent application for what was simply called "Display", a bubbling table top sign.   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. Sealed glass tubes with a bubbling liquid inside were first demonstrated by Benjamin Franklin.

Carl's concept for the Christmas tree bubble light, which he called an "Ornamental Illuminating Device ." was his second patent application and was finally granted in 1944. Before the patent was granted, he sent out samples to 10 of the biggest Christmas light companies in business, demonstrating how they could be used in  Christmas lights. Only one company, NOMA Electric Company, showed any interest.

In 1946 Noma Electric Co. was the first company to commercially sell bubble lites in the US. These lights were HUGE sellers, and rapidly became the most popular Christmas lights NOMA had ever sold. NOMA purchased the right to Carl Otis' latest patent, and he agreed to a royalty payment of 3 cents for each light produced. NOMA made more than 25 million Bubble Lites in the first two years of production,

Carl's royalty payment paid off.

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 making their own bubblers for sale during the 1947 Christmas season, calling them Kristal Snow Animated Candles.

Millions of  bubbling lights would continue to be made up until the 1970s, and NOMA lights were always the best sellers of any of the bubbling lights. Many of the bubble lights remain in use today, still bubbling away, just as they first did during the 1940s.