Previous columns have noted Ben Franklin’s expertise as an inventor, including his lightning experiments. Franklin was inspired by other inventors, especially French academic Thomas Dalibard, who actually performed the first lightning experiment.

Franklin wanted to duplicate Dalibard’s experiment and did so from Philadelphia’s Christ Church on Oct. 19, 1752.

According to his diary, Franklin made a cross of two light sticks, reaching the four corners of a handkerchief. Attached to the top of the stick was a sharp-pointed wire. Attached to the end of the twine, silk ribbon and a key.

The exact location of Franklin’s experiment places it possibly in mid-June in a now vacant lot near the intersection of 18th and Spring streets in Philadelphia.