While nowadays most string lights are LED bases, you can still add a good old Edison light bulb to your tree: This ornament shows a drawing from Edison’s 1880 light bulb patent. Shaped like an incandescent light bulb and featuring a gold-colored metal hook, it is ready to hang and could definitely inspire some bright ideas during the holiday season!

"Be it known that I, Thomas Alva Edison, of Menlo Park, in the State of New Jersey, United States of America, have invented an Improvement in Electric Lamps, and in the method of manufacturing the same of which the following is a specification. . . . The object of this invention is to produce electric lamps giving light by incandescence, which lamps shall have high resistance, so as to allow of the practical subdivision of the electric light."--Thomas Alva Edison. Filed with the United States Patent and Trademark Office November 4, 1879.

The patent act of 1790 established the rules for submitting a patent application. Each application had to be submitted with specifications, a patent drawing, and if possible a model of the invention. Eventually, models were no longer required.

The National Archives holds nearly three million patent case files from 1836-1956.