have come from a previous life, and to be picking up again 

 what they knew before. But Plato's boys were probably not 

 cramming a dozen subjects at once for which they had no 

 appetite and which they could not digest. 



As aids to ease of learning it may be remembered that just 

 as the first written language was in the form of pictures, so the 

 easiest way of imparting knowledge is by the graphic method. 

 Every scientific investigator knows the value of curves repre- 

 senting the mutual variation of two quantities. At a glance 

 one takes in the whole process, which would take hours to 

 comprehend from mere numerals. How easily we see the 

 meaning of the curve of barometric variation given on paper by 

 the little aneroids so common now. How much more trouble- 

 some to understand and remember a set of numbers representing 

 the- same thing. 



Similar curves may be employed in other studies. For 

 example, in history as illustrated in Diagram III. where, with the 

 accompanying graphic symbols, they will be found to convey to 

 most minds, I think, a clearer and more permanent view of the 

 whole subject, and its relations of time and magnitude than any 

 written description. The line at the bottom of the diagram 

 measures time, and is divided in decades from A.D. 1700 to 

 1880. On the next line above is indicated the duration of the 

 various reigns, and above that, just under a line which forms the 

 datum of curves, the great wars are shewn, with the cost of each 

 represented by a vertical arrow-pointed line, each unit of which 

 represents ^"10,000,000. A few of the great battles are denoted 

 by their initial letters. The curves represent the rise and fall of 

 several important National characteristics, including the National 

 debt, capital, population and railroad construction. The im- 

 practicability of using a similar unit in the construction of all 

 these curves is in some respects a defect, but it does not interfere 

 with a study of their relative rise and fall as compared quali- 

 tatively with each other. 



Various great events in history are indicated by their 

 appropriate graphic symbols. The thistle " scored out " by a 

 line drawn through it indicates the political extinction of Scot- 



