The terminals of an open magnetic circuit, or the ends of a magnetized mass of iron.
Porcelain. A fine variety of earthenware, valuable for insulators and insulating purposes.
Porosity. The state or property of having small interstices or holes. The opposite of density.
Porous Cup or Cell. A cup or cell made of pipe-clay or of unglazed earthenware through which a current of electricity can pass when wet or in a liquid. Porous cups are used in cells and batteries to keep two liquids apart, and yet permit electrolysis and electrolytic conduction.
Positive Currents. Currents which deflect the needle to the left.
Positive Electricity. The current that flows from the active element, the zinc in a battery, to the carbon. The negative electricity flows from the carbon to the zinc.
Positive Electrode. The electrode which is connected with the positive pole of a source of electric energy.
Positive Feeders. The lead or wire in a set of feeders which is connected to the positive terminal of the generator.
Positive Plate. In a voltaic cell, the plate which is acted upon and corroded. The current from the positive plate is negative electricity.
Positive Pole. The N pole in a magnet or magnetic needle. So called because it seeks the north or negative pole of the earth.