Originally published in 1800. CALCULUS OF FINITE DIFFERENCES by GEORGE BOOLE. PREFACE: IN the following exposition of the Calculus of Finite Dif ferences, particular attention has been paid to the connexion of its methods with those of the Differential Calculus a connexion which in some instances involves far more than a merely formal analogy. Indeed the work is in some measure designed as a sequel to my Treatise on Differential Equations. And it has been composed on the same plan. Mr Stirling, of Trinity College, Cambridge, has rendered me much valuable assistance in the revision of the proof sheets. In offering him my best thanks for his kind aid, I am led to express a hope that the work will be found to bo free from important errors. GEORGE BOOLE. QUEEN'S COLLKOE, CORK, April 18, 1800. PREFACE TO THE SECOND EDITION: WHEN I commenced to prepare for the press a Second Edition of the late Dr Boole's Treatise on Finite Differ ences, my intention was to leave the work unchanged save by the insertion of sundry additions in the shape of para graphs marked off from the rest of the text. But I soon found that adherence to such a principle would greatly lessen the value of the book as a Text-book, since it would be impossible to avoid confused arrangement and even much repetition. I have therefore allowed myself considerable freedom as regards the form and arrangement of those parts where the additions are considerable, but I have strictly adhered to the principle of inserting all that was contained in the First Edition. As such Treatises as the present are in close connexion with the course of Mathematical Study at the University of Cambridge, there is considerable difficulty in deciding thequestion how far they should aim at being exhaustive. I have held it best not to insert investigations that involve complicated analysis unless they possess great suggestiveness or are the bases of important developments of the subject. Under the present system the premium on wide superficial reading is so great that such investigations, if inserted, would seldom be read. But though this is at present the case, there is every reason to hope that it will not continue to be so; and in view of a time when students will aim at an exhaustive study of a few subjects in preference to a super ficial acquaintance with the whole range of Mathematical research, I have added brief notes referring to most of the papers on the subjects of this Treatise that have appeared in the Mathematical Serials, and to other original sources. In virtue of such references, and the brief indication of the subject of the paper that accompanies each, it is hoped that this work may serve as a handbook to students who wish to read the subject more thoroughly than they could do by confining themselves to an Educational Text-book. The latter part of the book has been left untouched. Much of it I hold to be unsuited to a work like the present, partly for reasons similar to those given above, and partly because it treats in a brief and necessarily imperfect manner subjects that had better be left to separate treatises. It is impossible within the limits of the present work to treat adequately the Calculus of Operations and the Calculus of Functions, and I should have preferred leaving them wholly to such treatises as those of Lagrange, Babbage, Carmichael, De Morgan, & c. I have therefore abstained from making anyadditions to these portions of the book, and have made it my chief aim to render more evident the remarkable analogy between the Calculus of Finite Differences and the Differential Calculus.