“Dr. Casey is an accomplished geometer, and this little book is worthy of his reputation. It is well adapted for use in the higher forms of our schools. It is a good introduction to the larger works of Chasles, Salmon, and Townsend. It contains both a text and numerous examples.” The \Journal of Education.” “Dr. Casey’s ‘Sequel to Euclid’ will be found a most valuable work to any student who has thoroughly mastered Euclid, and imbibed a real taste for geometrical reasoning.…The higher methods of pure geometrical demonstration, which form by far the larger and more important portion, are admirable; the propositions are for the most part extremely well given, and will amply repay a careful perusal to advanced students.” PREFACE. Frequent applications having been made to Dr. Casey requesting him to publish a ”Key” containing the Solutions of the Exercises in his ”Elements of Euclid,” but his professorial and other duties scarcely leaving him any time to devote to it, I undertook, under his direction, the task of preparing one. Every Solution was examined and approved of by him before writing it for publication, so that the work may be regarded as virtually his. The Exercises are a joint selection made by him and the late lamented Professor Townsend, s.f.t.c.d., and form one of the finest collections ever published. JOSEPH B. CASEY. 86, South Circular-road, December 23, 1886. Price 4/6, post free.] THE FIRST SIX BOOKS OF THE ELEMENTS OF EUCLID, With Copious Annotations and Numerous Exercises. BY JOHN CASEY, LL.D., F.R.S., Fellow of the Royal University of Ireland; Vice-President, Royal Irish Academy; &c. &c. ________________ Dublin: Hodges, Figgis, & Co. London: Longmans, Green, & Co. ________________ OPINIONS OF THE WORK. The following are a few of the Opinions received by Dr. Casey on this Work:— “Teachers no longer need be at a loss when asked which of the numerous ‘Euclids’ they recommend to learners. Dr. Casey’s will, we presume, supersede all others.”—The Dublin Evening Mail. “Dr. Casey’s work is one of the best and most complete treatises on Elementary Geometry we have seen. The annotations on the several propositions are specially valuable to students.”—The Northern Whig. “His long and successful experience as a teacher has eminently qualified Dr. Casey for the task which he has undertaken.…We can unhesitatingly say that this is the best edition of Euclid that has been yet offered to the public.”—The Freeman’s Journal. From the Rev. R. Townsend, F.T.C.D., &c. “I have no doubt whatever of the general adoption of your work through all the schools of Ireland immediately, and of England also before very long.” From George Francis FitzGerald, Esq., F.T.C.D.