THE TRISECTION OF AN ANGLE 33 



square root. The mathematician knows that such a thing 

 cannot be ; but the trisector virtually says it can be, and 

 is bound to produce it to save time. This is the misfortune 

 of most of the solvers of the celebrated problems, that they 

 have not knowledge enough to present those consequences 

 of their results by which they can be easily judged." 



De Morgan gives an account of a " terrific " construc- 

 tion by a friend of Dr. Wallich, which he says is "so 

 nearly true, that unless the angle be very obtuse, common 

 drawing, applied to the construction, will not detect the 

 error." But geometry requires absolute accuracy, not a 

 mere approximation. 



