THE discussion in your last part on methods of teaching elementary geometry reminds me that at a period when I was teaching the subject to a considerable number of pupils, I frequently overcame the difficulties of very young or inapt students by commencing with the study of a solid, such as a cube, encouraging the pupils to frame definitions for the parts of the object. The ideas existing in the child's mind of a solid, a plane, a line, and a point, were thus put into words in an order the reverse of that in which they would have been had Euclid been used. The chief properties of parallelograms and triangles followed, and were easily discovered by the use of a pair of compasses, scissors, and paper, and that at an age when Euclid was a sealed book. I believe children can be most easily taught to solve problems in plane geometry when they occur in connection with early instruction in practical solid geometry. Most children try to draw, and if they were encouraged to represent simple objects by “plans” and “elevations,” the necessity of obtaining a knowledge of how to describe the forms presented to them would frequently carry the pupils through a large number of the principal problems of plane geometry with a pleasure they could not experience if the “problems” were put before them, without any reason for their solution but the teacher's command. The powers of truthful representation gained by such teaching, would be of the utmost value to thousands who would never attempt to learn “Euclid;” whilst, so far as I am able to judge, it is more likely to prepare the boy to read formal works on geometry with pleasure than to create a distaste for the study.