Work and Energy—
Work done when force overcome or yielded to through any distance.
Gravity does work when body falls.—Work done against gravity in lifting a body. Foot-pound, unit of work.
A body which has power to do work has “energy”.—May have in consequence of motion, or of position, or of being heated, etc., etc.
Conservation of energy.—Transformation of energy.
THE TEACHING OF CHEMISTRY.
By Clare de Brereton Evans, D.Sc. (Lond.).
The committee appointed by the British Association in 1889 to inquire into the “Present Methods of Teaching Chemistry,” gave it as their opinion that “the high educational value of instruction in physical science has never been exhibited to its full advantage in most of our educational institutions,” and it will be admitted by the majority of those who interest themselves in the teaching of chemistry in girls’ schools that in spite of the growing tendency towards more rational methods of imparting the subject, the progress made in this direction during the last eight years has not been great enough to warrant any change in the above dictum.
After all that has been said and written about the difference between instruction and education, it should be unnecessary to reiterate that the object of our schools is not so much to develop the memories of the children as their capabilities, their powers of reasoning and doing, and although the attainment of this object is brought about chiefly no doubt by the method of teaching, it is also dependent upon the subject taught.
Elementary physical science as a basis for chemistry teaching.Natural science is specially valuable in calling into action at once the logical and practical faculties, training simultaneously the mind, the eye and the hand; but it is necessary in order to avoid teaching the subject dogmatically to make the course progressive—to preface lessons in chemistry, for example, by a preliminary ground-work of physics sufficient to render the chemistry intelligible. Elementary physics is the logical sequence of arithmetic, and may be taken up with the greatest advantage as soon as the four simple rules of arithmetic have been mastered; moreover the practical application of these rules afforded by simple measurements of length, area and volume is of immense use, not only because each pupil verifies for herself in this way the rules she has learnt to apply on paper, but also because arithmetic is thus shown to be of practical and not merely theoretical value. If children were taught from the beginning to make practical use of their arithmetic one of the greatest difficulties with which the science teacher has to contend later on would be obviated, that namely of explaining the application of mathematics to the solution of simple chemical and physical problems.