LECTURES ON QUATERNIONS: CONTAINING A SYSTEMATIC STATEMENT OF A NEW MATHEMATICAL METHOD. With numerous Illustrative Diagrams, and with some Geometrical and Physical Applications. By SIR WILLIAM ROWAN HAMILTON, LL.D., M.R.I.A., Andrews' Professor of Astronomy in the University of Dublin; Royal Astronomer of Ireland, &c., &c. 8vo. cloth boards, price 21s.

A TREATISE ON HEAT. PART I.: THE THERMOMETER, DILATION, CHANGE OF STATE, AND LAWS OF VAPOURS. By the REV. ROBERT V. DIXON, A.M., Rector of Clogherny, Diocese of Armagh; Late Fellow of Trinity College; and Erasmus Smith's Professor of Natural and Experimental Philosophy in the University of Dublin. 8vo. cloth boards, price 12s. 6d.

THE ELEMENTS OF PLANE AND SPHERICAL TRIGONOMETRY, with the Nature and Properties of Logarithms, &c., for the use of Students in the University. By THOMAS LUBY, D.D., M.R.I.A., Senior Fellow of Trinity College, Dublin. Part I. Third Edition, corrected and enlarged. 8vo. price 6s.

TWO GEOMETRICAL MEMOIRS

ON THE

GENERAL

PROPERTIES OF CONES OF THE SECOND DEGREE, AND OF SPHERICAL CONES. By M. CHASLES. Translated from the French, with Notes and Additions, and an Appendix on the Application of Analysis to Spherical Geometry. By CHARLES GRAVES, D.D., M.R.I.A., Dean of the Chapel Royal, and Fellow of Trinity College, Dublin. 8vo. cloth boards, price 6s. 6d.

ELEMENTS OF OPTICS. BY HUMPHREY LLOYD, D.D., Vice-Provost of Trinity College, Dublin. 8vo. cloth boards, price 6s. 6d.

TABLES FOR FACILITATING THE CALCULATION OF EARTHWORK, in the Cutting of Embankments of Railways, Canals, and other Public Works. By SIR JOHN MAC NEILL, LL.D., F.R.S., M.R.I.A., Professor of Practical Engineering, Trinity College, Dublin. 8vo. cloth boards, price 31s. 6d

DUBLIN:

HODGES, SMITH AND CO., 104, GRAFTON STREET.

BOOKSELLERS TO THE UNIVERSITY.

PRINCIPLES

OF

32.76

MODERN GEOMETRY,

WITH NUMEROUS APPLICATIONS TO

PLANE AND SPHERICAL FIGURES;

AND

AN APPENDIX,

CONTAINING QUESTIONS FOR EXERCISE.

INTENDED CHIEFLY FOR THE USE OF JUNIOR STUDENTS.

BY

JOHN MULCAHY, LL. D.,

LATE PROFESSOR OF MATHEMATICS, QUEEN'S COLLEGE, GALWAY.

Second Edition, Rebised.

C DUBLIN:

HODGES, SMITH & CO. 104, GRAFTON STREET,

BOOKSELLERS TO THE UNIVERSITY.

1862.