Stellar Evolution and its Relations to Geological Time

James Croll (1821–90) was self-educated, but on gaining a post at the Glagow Andersonian Museum had the time to explore his academic interests. Despite his lack of formal training, he quickly became a leading light of the Scottish Royal Geological Society. Using physics, mathematics, geology and geography he explored the pressing scientific questions of the time. In this, his final book, published in 1889, Croll divides his focus between 'the probable origin of meteorites, comets and nebulae', the age of the sun and the impact of the pre-nebular condition of the universe on star evolution. Using both proven facts and theories, Croll explores the ideas and hypotheses then current, frequently crediting colleagues for their work, and building on it. Croll, who from humble beginnings became a Fellow of The Royal Society and of St Andrew's University, writes in a style which makes his works accessible to a lay readership.

Part I. The Impact Theory of Stellar Evolution: Consideration of the facts which support the theory, and of the light which the theory appears to cast upon the facts; 1. Probable origin of meteorites; 2. Motion of the stars, how of such different velocities, and always in straight lines; 3. Motion of the stars not due to their mutual attractions; 4. Probable origin of comets; 5. Nebulae; 6. Binary systems; 7. Sudden outbursts of stars; 8. Star clusters; 9. Age of the sun's heat - a crucial test; Part II. Evidence in Support of the Theory from the Age of the Sun's Heat: Testimony of geology and biology as to the age of the sun's heat; Testimony of geology - method employed; The average rate of denudation in the past probably not much greater than at the present; How the method has been applied; Method as applied by Professor Haughton; Method as applied by Mr Alfred R. Wallace; Method as applied directly; Evidence from 'faults'; Time required to effect the foregoing amount of denudation; Age of the earth as determined by the date of the glacial epochs; Testimony of biology; Part III. Evidence in Support of the Theory from the Pre-nebular Condition of the Universe: Professor A. Winchell on the pre-nebular condition of matter; Mr Charles Morris on the pre-nebular condition of matter; Sir William R. Grove on the pre-nebular condition of matter; Evolution of the chemical elements, and its relations to stellar evolution; Sir Benjamin Brodie on the pre-nebular condition of matter; Dr T. Sterry Hunt on the pre-nebular condition of matter; Professor Oliver Lodge on the pre-nebular condition of matter; Mr. William Crookes on the pre-nebular condition of matter; Professor F. W. Clarke on the pre-nebular condition of matter; Dr G. Johnstone Stoney on the pre-nebular condition of matter; The impact theory in relation to the foregoing theories of the pre-nebular condition of matter; Index.

James Croll's final publication, of 1889, focuses equally on the age of the sun, 'the probable origin of meteorites, comets and nebulae', and the effect of the early universe on star evolution. The clarity of his explanations makes his work on these universal and essential subjects still accessible to all.