Rramjet:
A blimp or airship's profile is essentially elliptical in shape. A flat, circular object, viewed at an angle, also has an elliptical shape (you can try this with a coin, if you like). Given only an elliptical shape, it could be interpreted as a blimp's profile, or a flat circular object, viewed at an angle.
This would actually explain why one account describes a flat circular craft, while the drawings are of a blimp-shaped thing.
A blimp or airship's profile is essentially elliptical in shape. A flat, circular object, viewed at an angle, also has an elliptical shape (you can try this with a coin, if you like). Given only an elliptical shape, it could be interpreted as a blimp's profile, or a flat circular object, viewed at an angle.
This would actually explain why one account describes a flat circular craft, while the drawings are of a blimp-shaped thing.

