TRILINEAR CO-ORDINATES.

AN ELEMENTARY TREATISE

ON

TRILINEAR CO-ORDINATES,

THE METHOD OF RECIPROCAL POLARS,
AND THE THEORY OF PROJECTIONS.

BY THE REV.

N. M. FERRERS, D.D., F.R. S.

MASTER OF GONVILLE AND CAIUS COLLEGE,
HON. LL.D. OF THE UNIVERSITY OF GLASGOW.

FOURTH EDITION.

London:
MACMILLAN AND CO.
AND NEW YORK.

1890

[All Rights reserved.]

First Edition 1861, Second Edition 1866, Third Edition 1876, Fourth Edition 1890. 133536 OCT 8 1909

LIH
F41

PREFACE.

THE prominence which the modern geometrical methods - have recently acquired in the studies of the University of Cambridge, appears to justify the publication of a treatise devoted exclusively to these branches of Mathematics. This remark applies more especially to the method of Trilinear Co-ordinates, which forms the subject of the greater part of the following work. My object in writing on this subject has mainly been to place it on a basis altogether independent of the ordinary Cartesian system, instead of regarding it as only a special form of Abridged Notation.

A desire not unduly to increase the size of the book has prevented me from proceeding beyond Curves of the Second Degree.