THE appointment of a committee of the British Association on the teaching of elementary mathematics encourages the hope that that body will be able, after collecting the opinions of practical educators, to focus them with due wisdom into a scheme which will be generally acceptable, both to teachers and examiners. For success to be attained it is obviously necessary that those who are in actual touch with the work of teaching should state what, in their judgment, is desirable and practicable. Hoping that others besides myself will follow the example set some time ago by Mr. Hurst of Eton, I venture to write to NATURE a sketch of the conclusions to which an experience of many years at Charterhouse has led me.