Leyden Jar

I’m working on a Physics exercise and need support.

1.Why is the outer conductive layer helpful when charging the jar? It isn’t even in contact with the lid and water!

2.The simplest general equation for the capacitance(effectiveness holdingacharge) of a capacitor isC=εA/z. The three variables are: ε, the permittivity or polarizability of the insulating layer (in this case the glass or plastic); A, the total area ofeither conductive layerincontact withthe insulator; and z, the thickness of the insulating layer:What arethethree ways to improve a Leyden Jar, in theory, based on this equation?