from The Century Dictionary.
- noun An electric condenser made by having two thin metal plates separated by a layer of air, one plate being connected to a positive pole and the other to a negative pole from the same circuit.
- noun A condenser for steam in which air is used for cooling the condensing surface instead of water: used on some motor-cars.
Sorry, no etymologies found.
The only advantage I can see from reusing mine pits is that the accumulated water at the bottom might be used to improve condenser efficiency reducing capital expenditures vs an air-condenser and improving energy conversion efficiency per the same Carnot cycle.
With all the seriousness of a teacher of physics, Poe describes the lunar trip of one Hans Pfaall with his balloon, air-condenser, and cat.