Manuals of Elementary Science—Electricity

Abstract

THIS little work, of little more than a hundred pages, is a remarkable tour de force, since it contains in briefest language almost everything that can be taught, without using mathematical symbols, of the modern notions on electricity. It therefore well deserves to stand as a companion volume beside that remarkable primer of “Matter and Motion” of the late Prof. Clerk-Maxwell. The strong point of the present elementary work on electricity is the way in which it points out the connection between electrical (and magnetic) phenomena and the phenomena of other branches of physics as regulated by the law of the Conservation of Energy. So early as the sixth paragraph the fundamental idea of electric potential is introduced, a course which is surely to be commended, inasmuch as there is no more inherent difficulty in the mind of the beginner in conceiving of electricity as able to do work by moving from one position to another than of conceiving it as able to exert a force at a distance, while there can be no question that the former of these two conceptions is the more fruitful for expressing electric actions and reactions. The inherent connection between induction and charge is carefully insisted upon, and the beginner is told in simple language how the equal and opposite stresses between the two elements of an induction-pair, separated by an insulating medium, represent a store of energy whose seat is in reality in the intervening medium. Where so much pains has been taken to spare the beginner from having anything to unlearn, it is a pity that in the very first sentence our antiquated friends the “two imponderable fluids called positive and negative electricity” crop up. We also think it is a mistake to refer to a magneto-electric generator as a magneto-electric “engine” (as is done on page 107). The chapter on Electro-chemistry is admirable in every way. The following paragraph, on the perception of electricity, deserves to be quoted entire:—

Manuals of Elementary Science—Electricity.

By Prof. Fleeming Jenkin, F.R.S. (London: Society for Promoting Christian Knowledge, 1881.)