The Practical Astronomer Comprising illustrations of light and colours--practical descriptions of all kinds of telescopes--the use of the equatorial-transit--circular, and other astronomical instruments, a particular account of the Earl of Rosse's large telescopes, and other topics connected with astronomy

CHAPTER II.

Chapter 3141 wordsPublic domain

ON THE REFRACTION OF LIGHT.

Nature of refraction--Illustrated by experiments--Angle of refraction--Familiar experiments illustrative of refraction--Refraction explains the causes of many curious and interesting phenomena--Its effect on the heavenly bodies--On the twilight--Illustrated by figures

_page_ 41-53.

EXTRAORDINARY CASES OF REFRACTION IN RELATION TO TERRESTRIAL OBJECTS.

Extraordinary appearance of the coast of France from Hastings--Appearance of a ship seen by Captain Colby, beyond the coast of Caithness--Scoresby’s view of his father’s ship when beyond the horizon--Phenomenon near the Himalaya mountains--Bell Rock light-house--Summary statement of the diversified effects of refraction--Reflections on the beneficent and diversified effects produced by the law of refraction--It increases the length of the day, particularly in the polar regions--Is the cause of that splendour which appears in the objects around us--Quantity of refraction in respect to terrestrial objects, and its utility--Its effects may be more diversified in other worlds

_page_ 53-63.