Hang glider under tow. Philadelphia, USA. 1920s.
Author died more than 70 years ago - public domain.
Loaded by <a href="//commons.wikimedia.org/wiki/User:BatteryIncluded" title="User:BatteryIncluded">BatteryIncluded</a> 15:37, 31 December 2007 (UTC)
www.aeroclubpa.org/history.html