38 THE POPULAR SCIENCE MONTHLY. 



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 over- 

 power 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-ordi- 

 nate 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 invalu- 

 able for both student and instructor. In fact, no lesson is more stimu- 

 lating 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 with- 

 out producing weariness, but even with a power to give a sense of sur- 

 prise 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 falla- 

 cies he is to examine should be such as he had not previously consid- 

 ered. 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 stu- 

 dents 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 ex- 

 pected of them in the future like troops after their first fight. After- 

 such an examination the instructor will find his class much more dis- 

 ciplined and more ready to exert themselves in the intellectual wrest- 

 ling. 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 



