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COLOUR-PATCH APPARATUS.THE ROMANCE OF SCIENCE.
COLOUR MEASUREMENT
AND
MIXTURE.
With Numerous Illustrations.
BY
CAPTAIN W. de W. ABNEY, c.b., r.e., d.c.l., f.r.s.
PUBLISHED UNDER THE DIRECTION OF THE COMMITTEE
OF GENERAL LITERATURE AND EDUCATION APPOINTED BY THE
SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.
SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.
LONDON: NORTHUMBERLAND AVENUE, W.C.;
43, QUEEN VICTORIA STREET, E.C.
BRIGHTON: 135, NORTH STREET.
NEW YORK: E. & J. B. YOUNG & CO.
1891.
PREFACE.
Some ten years ago there were three measurementsof the spectrum which I set myself to carryout; the last two, at all events, involving newmethods of experimenting. The three measurementswere: (1st) The heating effect; (2nd) theluminosity; and (3rd) the chemical effect on varioussalts, of the different rays of the spectrum.The task is now completed, and it was in carryingout the second part of it that General Festing, whojoined me in the research, and myself were ledinto a wider study of colour than at first intended,as the apparatus we devised enabled us to carryout experiments which, whilst difficult under ordinarycircumstances, became easy to make. Ontwo occasions, at the invitation of the Society ofArts, I have delivered a short course of lectures onthe subject of Colour, and naturally I chose totreat it from the point of view of our own methodsof experimenting; and these lectures, expanded andmodified, form the basis of the present volume.
As a treatise it must necessarily be incomplete,as it scarcely touches on the history of the subject—apart which must always be of deep interest.The solely physiological aspect of colour has alsobeen scarcely dealt with; that part which thephysicist can submit to measurement being thatwhich alone was practicable under the circumstances.
W. de W. Abney.
South Kensington,
1st May, 1891.
CONTENTS.
CHAPTER I.
Sources of Light—Reflected Light—Reflection from Roughened Surfaces—Colour Constants p. 11
CHAPTER II.
A Standard of Light—Formation of the Spectrum by Prisms and by the Diffraction Grating—Wave-lengths of the principal Fraunhofer Line—Position of Colours in the Spectrum p. 17
CHAPTER III.
The Visible and Invisible Parts of the Spectrum—Methods for showing th