AN INTRODUCTION TO GEOMETRY. FOR THE USE OF BEGINNERS. CONSISTING OF EUCLID'S ELEMENTS, BOOK I. ACCOMPANIED BY NUMEROUS EXPLANATIONS, BY JOHN WALMSLEY, B.A., MEMBER OF THE LONDON MATHEMATICAL SOCIETY; MAR25 BODLEIAM LIE OXFORD New Edition, revised, corrected, and improved. LONDON: FRANCIS HODGSON, 89 FARRINGDON STREET. 1884. 1831. £.12 SECTION II., PROPS. 7-12.-Second Case of Equality of Two SECTION III., PROPS. 13-17.-Angles which Two Intersecting Straight Lines make with one another and with a Third SECTION IV., PROPS. 18-25.-Inequalities of Parts of Triangles, SECTION VIII., PROPS. 33, 34.—Parts of a Parallelogram... SECTION IX., PROPS. 35-42.-Parallelism in relation to Equivalent SECTION X., PROPS. 43--45.-Complementary Parallelograms and the Reduction of Rectilineal Figures to Parallelograms of SECTION XI., PROPS. 46-48.-Squares and the Sides of the Right- NOTE.-The Diagrams at the end are upon tough paper, and each of PREFACE TO SECOND EDITION. THE principles of this little work have met with much approbation from teachers and authorities of high standing. In the preparation of a new edition, therefore, a great effort has been made to carry out those principles fully, while providing for as small an expenditure of time and labour on the part of both pupil and teacher as will be effective. The book is now stereotyped, and hence teachers may use it with the assurance that it will meet with little or no alteration in future. In reference to the changes which have been made, it may be noted that the extracts from the London University Matriculation papers have apparently disappeared. All the problems in them, however, which were new or otherwise important, have been absorbed into the "Papers for Revision." Room was made for them by omitting some less useful questions, and by adding one new paper. In place of the portions of Matriculation papers referred to, those of the Science and Art Department have been brought up to date, and now form a most useful series of ten. In the body of the work, questions formerly occurred here and there which were found to be more or less vague, and therefore to invite guessing answers. Some of these have been amended, and others removed. Other questions, again, involved repetition carried somewhat to excess, and for that reason have been considered unnecessary. The bulk of the work is still what it was; and the differences, which will be at once evident on comparison with the former edition, are mainly due to re-arrangement of matter. This has been carried out in accordance with the suggestions of experience, with a view to render the work more practically useful as a class-book. We may add here that anyone who will examine the papers recently set in the London University Matriculation Examinations, or those of the Science and Art Department, will perceive that for these examinations some such training as is afforded in this book is fast becoming not only desirable, but indispensable. It appears also to be becoming more and more so in all other examinations of good reputation. August, 1884. J. W. |