Sale 707 The Knapp Collection of Airmail Flights

1870-71, Ballon Monté covers, group of 11, all are normal folded letters; the lot comprises États-Unis, Vaubon, Général Uhrich, Jules Favre, Franklin, Ville de Paris, Parmentier, Bayard, Newton, Duquesne and Général Bourbaki; all have condition problems with some combination of the letter, the stamp or the markings, most not being particularly serious. Also includes a reproduction of an 1873 Membership application for The Aéronautic-Club of Paris. A useful group.
Estimate $500 - 750.