Excerpt from Geometric Properties Completely Characterizing, the Set of All the Curves of Constant, Pressure in a Field of Force
In the Princeton Colloquium lectures, 1909, Professor Edward Kasner of Columbia University pointed out several Это и многое другое вы найдете в книге Geometric Properties Completely Characterizing, the Set of All the Curves of Constant, Pressure in a Field of Force (Classic Reprint) (Eugenie Maria Morenus)