enough by sticking two large sheets together. Some printers can now rule this paper in squares to suit the convenience of the worker; but these guiding-lines ought to be faint, and not so heavy as to overpower the lines of the chart. So far I have been speaking of charts for the class-room. Perhaps, in their own good time, such economic charts can be bought of educational agencies. But ordinary co-ordinate paper, on a small scale, is the best form in which to first arrange the chart. It can be purchased in sheets at a small price, and is invaluable for both student and instructor. In fact, no lesson is more stimulating to a class than to give them the data of a subject and ask them to put it into graphic form. For the first time they begin to realize that statistics are not dry; indeed, any one who has turned over the pages of Walker's "Statistical Atlas" will find out for himself how the columns of census tables can talk to him in forms and colors without producing weariness, but even with a power to give a sense of surprise at the interest they excite.
8. When the instructor comes to examinations he will find several difficulties. In making out questions he ought to keep in view that they should be arranged so as to test not the memory, but the power of the pupil to apply principles. For this reason the ideal paper should contain nothing which the student has seen in that form before. The facts he is called upon to explain ought to be fresh ones, and the fallacies he is to examine should be such as he had not previously considered. But for practical purposes it seems best to remember that a class is composed of all kinds of persons, and, while the majority of the questions should be of the character which I have described, yet at least a few easier and more encouraging questions should be set. The student should be instructed to study each question with care; and avoid haste in answering, before he is sure that he has really caught the point and essential idea of the question. Fairly good students often write about the question, but do not answer it. It should be definitely understood that no credit is given for such answers. Then, also, the examination can be used as a teaching process; since, by inserting an important subject, the attention given to it at these times will be such as to keep it from speedy oblivion. Moreover, it will be well, after the examination, to read a good and a poor answer to each question before the class. They will know better what is expected of them in the future—like troops after their first fight. After such an examination the instructor will find his class much more disciplined and more ready to exert themselves in the intellectual wrestling. The vigorous preparation for the examination has really given them a better grasp of the subject, and the teacher can easily bring on a warm discussion now, because they really know something and feel that they know it.
9. When first approaching the study, it has been found to be of service to some students to suggest that on the first reading of the