United States. Army Division of Military Aeronautics · leaf 240
id) Ring of the valve _B. (figure 5). — The ring of the valve is a cir- cular reenforcement of the opening of the valve and consists of two washers (a a') 2 thick- nesses of double -ply fabric fastened down and having an internal diameter equal to that of the opening. These two washers fastened,…
Balloons · Aeronautics, Military
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
![An illustration from [Balloon notes], 1917, leaf 240](https://img.insideoutlibrary.com/img/1024/ia-balloonnotes01unit-240-0.webp)
