In a letter dated May 23, 1785, Benjamin Franklin refers to “my double spectacles” and proffers a sketch. This letter, and other documents, provide much of the evidence for definitively naming Franklin the inventor of bifocals. A version of a drawing from this letter is above.

He describes the difficulties that every person who wears bifocals (hello: waves to camera) encounters on their way to deciding to wear bifocals: “The same convexity of glass, through which a man sees clearest and best at the distance proper for reading, is not the best for greater distances. I therefore had formerly two pair of spectacles, which I shifted occasionally, as in travelling I sometimes read, and often wanted to regard the prospects.”
Read More

To this day, only one U.S. President has been awarded a patent for an invention: Abraham Lincoln. On May 22, 1849, Lincoln received Patent No. 6469 for a device to “buoy vessels over shoals,” an invention which was never manufactured.

His application reads: “Be it known that I, Abraham Lincoln, have invented a new and improved manner of combining adjustable buoyant air chambers with a steam boat or other vessel for the purpose of enabling their draught of water to be readily lessened to enable them to pass over bars, or through shallow water, without discharging their cargoes …”
Read More

The first meeting of the American Red Cross was held in Clara Barton’s home in Washington, DC, on this date in 1881.

Barton had learned about the International Red Cross and had performed work similar to the Red Cross during the American Civil War. She had organized nursing stations near battlefields—a man she was tending to died in her arms after he was shot while she was administering care to him; the bullet cut through her sleeve and hit him—and she distributed food and supplies on the front lines.
Read More