THE present volume contains 93 papers numbered 706 to 798, published, with the exception of one series, for the most part in the years 1878
to 1883. This series is constituted by the articles which Professor Cayley
wrote for the Encyclopaedia Britannica between the years 1878 and 1888 ;
it seemed desirable to place these together in the same volume, in spite
of the departure from the chronological arrangement which governs the
sequence of the papers in the volumes generally. The Syndics of the
University Press desire to acknowledge their obligation to Messrs Adam
and Charles Black, Publishers of the ninth Edition of the Encyclopedia
Britannica, for their courteous consent in allowing these articles to be
included in the Collected Mathematical Papers. Exact references to the
volumes, from which the articles are extracted, will be found in the Table
of Contents.