The following method of establishing the existence and properties of the Focal Circles of a Circular Cubic is, as far as I know, new, and it has the advantage of dispensing, almost entirely, explicitly with analysis, while many of the properties can be proved without using the complicated method of generating the curve given in Salmon. The results which I have arrived at in connexion with the Nodal Cubic and Cuspidal Cubic are not given in Salmon.