68 Mb HOLDITCH, ON ROLLING CURVES. 



If n = 1 the curve is. of one lobe, and if also k 2 = it is an ellipse ; 

 and examples are given when h % = 2, 4, 10 and 20 in figures 2, 3, 4, 5, 

 C being the fixed centre; if k 2 = — 2, — 4, — 6, — 15, — 20, the repre- 

 sentations are given in figures 6, 7, 8, 9, 10, in all which figures, only 

 the upper half of the lobe is drawn, as the lower is similar and equal 

 to it : and although in some of the figures the radius vector has swept 

 over more than half a circumference, it has returned so that the semi- 

 lobe has terminated when 9 — ■*. 



If n = 2, 3, 4, &c, curves of 2, 3, 4, &c, lobes may be traced from 

 the above table, and are readily laid down. 



If a = 16.95, and b = 6.95, the following is another table for a great 

 variety of self-rolling curves: 



When r - b 



