BY D. E. JONES, B.Sc. LECTURER ON PHYSICS AT THE UNIVERSITY COLLEGE OF WALES ABERYSTWYTH London MACMILLAN AND CO. AND NEW YORK 1 888 PREFACE The value of the mental training obtained by solving algebraical problems and geometrical riders has so long been acknowledged that these form an essential part in all mathematical teaching. Although similar practice is quite as necessary in studying physical science, it is by no means equally easy for the student of physics to obtain it, for only the more recent textbooks contain any numerical examples, and these are generally insufficient in number and not carefully graduated. It is quite common to find students who have a correct knowledge of the general principles of physics, and can apply it intelligently in making a physical measurement, but who are yet unable to solve an easy problem or to calculate the results of their experimental work. There can be no doubt that the best way of acquiring the necessary practice is by means of a regular series of quantitative experiments in the laboratory carried on side by side with the more general work of the lecture-room; but such concurrent work is not always practicable, especially with large classes and in the earlier stages. Just as the student of dynamics has at first to confine his attention to questions of a more or less ideal nature, so in some departments of experimental physics (for example in electrostatics) the beginner must for a while content himself with somewhat theoretical problems in place of laboratory work. |