1To Benjamin Franklin from Jacques Barbeu-Dubourg, 1 April 1773 (Franklin Papers)
...machine ne differe presque d’un parasol, que par quelques petits accessoires, qui s’y...
2To Benjamin Franklin from Jean-Pierre Blanchard, [c. April 1782] (Franklin Papers)
...of ten-foot-long wings would create a parasol 20 feet in diameter; the mechanics of...