author proceeds to prove the associative law, and then, after dealing with the equality of non-coinitial vectors, gives many interesting uses of the generalised vector algebra. The proof of Pascal's theorem gives a striking example of the power and simplicity of the new method, and the whole treatment of conics will delight the student of projective geometry. Altogether the book is a very original and striking contribution to a fascinating branch of mathematics. BOOK-PRODUCTION NOTES By J. H. MASON The important work done by the private presses of the last twenty-five years will probably be found to be in its results more far-reaching than that done in any other artistic craft. For, in addition to giving the world monumental editions of chosen works, such as the _Kelmscott Chaucer_, the _Doves Bible_, and the _Ashendene Dante_, they have set up the right standards in type lettering, margins, spacing, paper, illustration, and binding. Even in binding they have set a standard that can be widely applied; for the linen back and paper sides that were good enough for a Kelmscott Press book set an example of wholesome plainness that has done a great deal to improve the task of publisher and public. The publisher of this generation is in strong reaction, as a rule, against the cloth gilt extra of his father and grandfather. _The Artistic Crafts Series_, edited by Professor W. R. Lethaby, is a notable example of such a plain, useful cover. One of the earliest, the first I think, of this series was that dealing with Bookbinding, and doubtless this was largely the cause of the series starting right in the matter of covers. One regrets that there wasn't a printer available to have influenced the choice of type and dimensions of the page--the series that is satisfactory in both respects has not yet been published. Type, paper, proportions of printed page and margins, and finally the cover, are the chief matters to be considered in producing a satisfactory book, and all of these cost no more--with the exception of paper--when right than when they are unsatisfactory. Even in the matter of paper, there is a wide range of choice, in normal times, at every price above the very cheapest.