Ancient Ideas .—Closely related to the idea of infinity, in the treatment of which we so neglect our opportunities in the teaching of mathematics in our high schools, is the question of the form of tbe universe about us. It may not be possible, by casual conversation, to present such a subject to. the classes in any satisfactory manner, but we shall teach mathematics with greater earnestness of purpose for having ourselves considered, even though superficially, this and similar problems.