The volume called Higher Mathematics the first edition of which was published in 1896 contained eleven chapters by eleven authors each chapter being independent of the others but all supposing the reader to have at least a mathematical training equivalent to that given in classical and engineering colleges. The publication of that volume is now discontinued and the chapters are issued in separate form. In these reissues it will generally be found that the monographs are enlarged by additional articles or appendices which either amplify the former presentation or record recent advances. This plan of publication has been arranged in order to meet the demand of teachers and the convenience of classes but it is also thought that it may prove advantageous to readers in special lines of mathematical literature. It is the intention of the publishers and editors to add other monographs to the series from time to time if the call for the same seems to warrant it. Among the topics which are under consideration are those of elliptic functions the theory of numbers the group theory the calculus of variations and non-Euclidean geometry; possibly also monographs on branches of astronomy mechanics and mathematical physics may be included. It is the hope of the editors that this form of publication may tend to promote mathematical study and research over a wider field than that which the former volume has occupied.