MAY 25 1901 



ISOGONIC TRANSFORMATION.* 



T. G. Poats. 



In this paper the expression Isogonic Transformation is used 

 to indicate the transformation of a figure which results from 

 t he projection of its points along circular arcs which measure 

 equal angles at the feet of the ordinates of the respective 

 points. For instance, if the ordinate drawn to P' (Fig. 1) 



Fig. l. 



is turned through an angle a about its foot and, likewise, 

 the ordinates from all the other points of the circumference 

 are turned each through the same angle a, the resulting figure 

 is the isogonic transformation of the circle. 



* Presented in abstract to The Academy of Science of St. Louis, Jan. 21, 

 1901. 



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