PART I - A re-print, with additions, of the remarks on the Colours of Double Stars contained in the third chapter of the CYCLE OF CELESTIAL OBJECTS, under the title of “A Glance at the Sidereal Heavens.”

Summary

ON THE COLOURS OF DOUBLE STARS

The Author's intent

Under this title we are not about to inflict on the reader any of the extravagant notions of the ancients—aye, not even the best of them—concerning the essence of hues and tints, they being utterly unsupported either by reason or experiment. Nor is it intended to theorize under modern advantages upon light and rays, the seductions of harmony and contrast, nor to jump at any of the remaining uncertainties of the question. The present light sketch is merely handed forth to investigate that property of colours which affects the sight only: and, if the absolute tints of double stars are determined at special epochs, much will be contributed towards the mysterious laws which regulate such variations as may be observed. Upon this understanding, we will open our fire with the following extract from the Prolegomena to my

CYCLE OF CELESTIAL OBJECTS

Initiatory Remarks

For the sake of the tyro, it may be proper to premise that the light of the two stars composing the double one is frequently found to be of very dissimilar intensity, and often of very dissimilar colours; and no one who has ever directed a telescope to the heavens can have failed to be struck with the brilliant hues they present, especially such lovely objects as γ Andromedæ, α Herculis, and ε Boötis.