CONTENTS. 



CHAPTER I. Efficiency of the Plug-cock Fog Chamber. 



Page 



1 . Introduction i 



2. The variables. Table i i 



3. Approximate computations of p^ and p 2 . Table 2; fig. i 3 



4. Definite computations of p 1 and p 2 . Table 3 6 



5. Computation of vjv. Table 3 ; fig. 2 7 



6. Approximate computation of r t 8 



7. Approximate computation of p 2 9 



8. Rate of reheating of the fog chamber. Table 4; fig. 3 10 



9. Definite computation of T I( p lt r 2 , p 2 , etc. Table 5 n 



10. Conclusion 13 



CHAPTER II. Changes of Vapor Nucleation 0} Dust-free Wet Air in Lapse 

 of Time, together with Effects of the Limits of Pressure between which 

 a given Drop Takes Place, on the Efficiency of the Fog Chamber. 



11. Introduction. Table 6; fig. 4 14 



1 2. Data. Tables 7 and 8 ; figs. 5 and 6 17 



13. Explanation. Table 9 21 



14. The effect of vapor pressure. Table 9; fig. 7 22 



15. New data for vapor nucleation in lapse of time. Tables 10 and 1 1 ; figs. 8, a, b . . 24 



16. Effect of barometer 33 



17. Effect of temperature 33 



1 8. Effect of ionization. Table 12; fig. 9 33 



19. Mean results. Tables 13 and 14, fig. 10 36 



20. Nucleations depending upon dp/ 'p. Table 15 37 



21. Possible suggestions as to the temperature effect 39 



22. Another suggestion 41 



23. Conclusion 41 



CHAPTER III. The Nucleation Constants of Coronas. 



RESULTS WITH A SINGLE SOURCE OF LIGHT. 



24. Introduction 43 



25. Apparatus and methods. Fig. 1 1 43 



26. Equations and corrections. Tables 16 and 17; figs. 12 and 13 45 



27. Data for moderate exhaustions 49 



28. Remarks on the tables and charts 49 



29. Data for low exhaustions. Table 18; figs. 14 and 15 51 



30. Data for high exhaustions. Table 19; fig. 16 54 



31. Standardization with ions 56 



32. Further data. Table 20; figs. 17 and 18 56 



33. The violet and green coronas. Tables 21 and 22; fig. 19 59 



34. Insertion of new values for m. Table 23 61 



35. Wilson's data and conclusions. Table 24 62 



36. Longer intervals between observations. Conclusion 63 



DISTRIBUTIONS OP VAPOR NUCLEI AND OF IONS IN DUST- FREE WET AIR. CON- 

 DENSATION AND FOG LIMITS. 



37. Introductory 65 



38. Notation 65 



39. Data. Tables 25, 26, 27, 28, and 29 65 



v 



