But my concept of airships remains vague, partially influenced by Burroughs and his very vague descriptions of airships in Barsoom. We know they have some sort of tanks holding a "ray" that keeps them aloft (how that works, I don't know) and are moved along by a screw that acts like a propeller.
I have two different ideas for airships in Barsoom:
- I see airships as having sails, rigging, and big ol' tanks of devices that provide anti-gravitational force help the ships stay airborne. These "lift engines" are rare, expensive, and only maintained by a powerful guild that knows the secrets of Ancient technology involved in lift engines. These airships are more maneuverable, are faster, and tend to be controlled by military or governmental organizations.
- I also see airships as essentially blimps or dirigibles with sails, with ship's hulls hanging below as gondolas. These will be more common, use an orichalcum gas to gain lift, but they lack the maneuverability and speed of true airships. They also need to be lighter, so are harder to make into armored battle ships like lift engines allow.
All that said, airships are still only used by the wealthy and the priveleged. Airship travel is expensive and rare, and trade and travel still depends heavily on dangerous caravan trips overland.