WRIGHT: METHOD FOR PLOTTING RECIPROCALS 



187 



corresponding radiating lines {x'). In figure i these points of 

 intersection are indicated by crosses. The curve KB' passing 

 through the x' points may prove to be a straight hne as in the 

 case shown in figure i . In this particular case the line intersects 

 the A'-axis at 2.4 and the Y-axis at 3.0; its equation is accordingly 



y = - 1.25X' -f 3.G0. 

 The equation of the x,y curve is therefore (by equation (i)) 



y (1.25X + i) = 3.00 

 the equation of a rectangular hyperbola. In case the line KB' 

 is not a straight line, but a curve for which the mathematical 

 expression can be ascertained, this expression can be converted 

 directly into the desired equation in ordinary coordinates. 



Fig. 2. — Illustrating the principle on which the foregoing method of plotting recip- 

 rocals is based. Thus the rectangular coordinate projection normal to the Z-axis 

 (front face of cube) becomes a projection with lines radiating from the center in 

 the projection planes normal to the X-axis or the F-axis of the orthogonal system 

 of spacial coordinates. 



The lengths of the intercepts of the radiating x' lines on 

 the vertical line at unit distance from the origin (x = i) are, 

 moreover, the reciprocals of the A'-scale values, or i/x. 



