Two ten-inch diameter aluminum plates are mounted on insulating stands. One of the plates is supported by an ebonite rod so that the separation between the plates can be varied from 1 mm to 20 cm. Potential for the plates is supplied by a Spellman 5 kilowatt low current power supply driven by a Heathkit 400 volt regulated power supply. Voltage is measured by a 5 kilovolt Ealing electrostatic voltmeter. The plates are charged with a wide separation to about five kilovolts and the potential is measured as a function of the separation as the separation is decreased. The relationship between potential and separation is not quite linear, due to the capacity of the electrostatic voltmeter. One can thus calculate the capacitance of this voltmeter. The experiment illustrates quite clearly the connection between potential and work/unit charge. The apparatus can also be used to demonstrate the exponential decay of a condenser and resistance. A block of porcelain or bakelite is placed between the plates and the voltage plotted as a function of time. One can then measure a surface resistance of about 10^12 ohms. The apparatus is also used to study the charge on the condenser held at a constant potential of 10 kv as a function of the separation of the plates. A ballistic galvanometer is placed in series with the charging circuit. Two stops are placed on the rod supporting the movable plate. One can measure the charge required to charge up the plates at either position and compare these values with the charge that flows when the plates are moved rapidly from one position to another.