Jempie,
Just a further note on Stevens for your records.
U.S. Patent # 661,826 Stevens, Leo New York, NY Controllable Balloon 1900-11-13. 2 pages.
Simine's U.S. Aviation Patent Database
http://invention.psychology.msstate....tDatabase.html
Bookmark it. It's proven useful to me more than once.
VBR
Rod