How many Christmas tree fires were started by candles?

Today, almost a fifth of all Christmas Tree fires are caused by a heat source such as a candle. Historically, the clip-on candle holder was invented in 1878 by Frederick Artz, which significantly increased the number of candles on recently cut trees, and thereby, the number of fires in homes. Insurers saw the risk and swiftly put an end to payments for fires that originated with candle-lit trees.

A new way of bringing the symbol of starlight to Christmas trees was clearly in demand. Thomas Edison created a string of lights, used to invigorate his lab with a row of light rather than just a single source. Howard Johnson, then president of Edison electric, expanded on the idea, designing a string of lights in 1882 to be wrapped around a tree. The team, under Edison’s direction, refined the design over 8 years, finally bringing a product to market that was featured at the White House lawn in 1923 by president Calvin Coolidge, becoming all the rage among those well-heeled enough to own the custom, hand-wired strings of light.