THE STRAIGHT LINE LAW 



219. As a further example, let us take a few laws and investi- 

 gate, in each case, the treatment necessary to make them com- 

 parable with the general straight line law. 



(1) 

 Then 



y - a Iog 10 ac 

 y^a {Iog 10 c+log 1( yr} 

 = a log lfl c f a Iog 10 a: 



Hence, to obtain a straight line y must be plotted vertically 

 and Iog 10 # horizontally. 



100 



80 



10 



60 



(2) y=ax+b Iog 10 a; 



Dividing throughout by x the law becomes 



V 

 Hence, to obtain a straight line - must be plotted vertically, and 



IP 



^- horizontally. 



Again dividing throughout by Iog 10 a; the law becomes 

 ti x 



