how are leyden jars inefficent?

Question

and are there ways to make them more efficent

Answer 1

Efficiency of what?

If you mean capacitance per unit volume (or unit mass), then you can make them more efficient by using glass cylinders of narrower radius, to the point where you have a hollow glass "straw" with a thin wire conductor on the inside wrapped with foil on the outside. This will eliminate all the volume on the inside of the jar, which does not contribute to the capacitance. The straw will have to be 'longer' to maintain the surface area, but the overall volume will be decreased, hence the volumetric 'efficiency' will be increased.

If you are speaking of capacitance per mass, then there are other glass materials with slightly higher relative permittivity's, so you can increase capacitance with the same sized jar.

How are they inefficient in the first place? They are a single-layer capacitor, whereas most 'real' capacitors are mutil-layer -- usually spiral wound long strips of flexible plate capacitor, or actual stacks of parallel single-layer plate capacitors.

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