Her PhD thesis was titled "Projective Theory of the Orthopoles". A large summary of this work was published in the
American Mathematical Monthly (June–July 1932, pages 327–338). The key idea is to associate a well chosen line-parabola to each ordinary line in the plane, in such a way that the orthopole of any element of the line-parabola belongs to initial line. This correspondence can be illustrated by the following figure (where
L is the line at infinity and
A1,
A2,
A3 the base triangle): Such a projective apparatus makes it possible, given a point in the plane, to determine the lines that admit this point as orthopole. In the general case, there are four of them (including the line at infinity and the complex lines if any). ==References==