398 
APPENDIX II 
problem was laid aside for a time, and attention paid to the equilibrium problem. 
The sequence of papers which have followed is— 
7. On the Radiative Equilibrium of the Stars. Monthly Notices, 77, p. 16 (1916). 
8. Further Notes on the Radiative Equilibrium of the Stars. Monthly Notices, 77, 
p. 596 (1917). 
9. On the Radiative Equilibrium of the Stars. A Correction. Monthly Notices, 
79, p. 22 (1918). 
10. On the Conditions in the Interior of a Star. Astrophysical Journ. 48, p. 205 
(1918). 
11. On the Pulsations of a Gaseous Star and the Problem of the Cepheid Variables, 
Parts I and II. Monthly Notices, 79, pp. 2, 177 (1918-19). 
12. Das Strahlungsgleichgewicht der Sterne. Zeitschrift fur Physik, 7, p. 351 (1921). 
13. On the Absorption of Radiation inside a Star. Monthly Notices, 83, p. 32 (1922). 
14. Applications of the Theory of the Stellar Absorption-Coefficient. Monthly 
Notices, 83, p. 98 (1922). 
15. The Problem of Electron Capture in the Stars. Monthly Notices, 83, p. 431 
(1923). 
16. The Absorption of Radiation inside a Star. Second Paper. Monthly Notices, 
84, p. 104 (1924). 
17. On the Relation between the Masses and Luminosities of the Stars. Monthly 
Notices, 84, p. 308 (1924). 
18. A Limiting Case in the Theory of Radiative Equilibrium. Monthly Notices, 85, 
p. 408 (1925). 
19. Electrostatic Forces in a Star and the Deviations from a Perfect Gas. Monthly 
Notices, 86, p. 2 (1925). 
Answers to various criticisms by J. H. Jeans are given in Monthly Notices, 78, 
p. 113; 85, p. 403. Minor references are— Scientia, 23, p. 9 (1918); Brit. Assoc. Report, 
1920, p. 34; Proc. Royal Institution, Feb. 23, 1923; Festschrift fur H. von Seeliger , 
p. 25 (1924). The following relate to side-problems— 
20. Cepheid Variables and the Age of the Stars. Observatory, 41, p. 379 (1918). 
21. The Sources of Stellar Energy. Observatory, 42, p. 371 (1919). 
22. Circulating Currents in Rotating Stars. Observatory, 48, p. 73 (1925). 
As a guide to papers 7-19 it is to be noted that the absorption coefficient 
was supposed to be independent of density up to 1921, the modern view of the 
absorption process being adumbrated (but not generally employed) in No. 12. 
This is the most important modification that the theory has undergone since 
ionisation was introduced in No. 8. Nos. 10 and 12 were intended to summarise 
results up to date, the former in elementary form and the latter fairly exhaus 
tively. No. 9 gives a rather important numerical correction to the formulae of 
Nos. 7 and 8, and the error is set right in all succeeding papers. Nos. 13-15 
adopt the theory of nuclear capture of electrons, but much of the work is applic 
able also to Kramers’ theory of capture adopted afterwards. Rosseland’s cor 
rection to the opacity (§77) appeared subsequently to No. 17, so that the 
present book is my first opportunity of presenting the theory with attention to 
this important point. The conclusion that dwarf stars are in the state of a perfect 
gas appears first in No. 17. The theory of Cepheids in Chapter vm is mainly 
contained in No. 11, but all numerical results have been revised in accordance 
with the later theory of the absorption coefficient. The chief additions are in 
§§ 131, 135-138. 
Investigations hitherto unpublished are contained in §§64-66, 90, 122, 157, 
160, 192, 193, 196, 229, 230, 231, 234-238, together with most of Chapters xi 
and xiij.