CONTENTS. xill 



PAGE 



Improved Method. 



5. Number of droplets. 6. Diameters of droplets. 7. Graded particles. 



II. Micro-photography of Fog Particles. 



General Results. 



8. Preliminary, g Apparatus and method. 10. Incidental phenomena. Pitting. 

 II. Dew. 12. Evaporation. 13. Moving and floating globules. 14. Graded particles. 



Specific Results. 



15. Photographic plates. 16. Tabulated results. 17. Remarks on the tables. 



Inferences. 



18. Precipitation per cubic centimeter. 19. Diameters and numbers. 20. Explanation 

 of discrepancies. 21. Summary. 



III. Results from Subsidence. 



22. Object and method. 23. Results. 24. Remarks on the tables. 25. Further 

 results. 



IV. Summary of all the Results Obtained for the Relation between Nucleation and 

 Coronal Diameter. 



26. Preparation of a table of reduction. 



Chapters VIII-IX. — Applications. 

 CHAPTER VIII. 



The Coronal Method of Estimating Atmospheric Nucleation 128 



I. Introductory. 2. Apparatus. 3. Diffusion from two opposed surfaces. 4. Mis- 

 cellaneous tests. 5. Diffusion from a single surface. 6. Absorption and decay of nuclei. 

 7. Effect of pressure difference. S. Precipitation per cubic centimeter. 9. Relation of 

 nucleation to aperture of corona. 10. Absence of electrification in cases of sudden con- 

 densation and of sudden evaporation. II. Conclusion. 



CHAPTER IX. 



The Variation in the Nucleation of the Atmosphere of the City of Providence 139 



Introduction. 



I. Preliminary. 2. Apparatus. 3. Classification. 



First Group of Observations. 



4. Early observations. 5. Plate-glass apparatus. New apertures. 



Second Group of Observations. 



6. Plan of tables and graphs. 7-16. Successive monthly data for 1903. 17-25. Succes- 

 sive monthly data for 1904. 



General Inferences. 



26. Efficiency of Apparatus. 27. Variability 2S. Wind effect. 29. Rain effect. 



30. Snow effect. 31. Cloud effect. 32. Solar effect absent. 33. Temperature 



effect. Cold-wave effect. 34. Local effect. 



Summary and Conclusions. 



35. Mean daily nucleations. 36. Mean monthly nucleations. 37. Occurrence 

 of maxima and minima of nucleation during the winter and the summer solstices, 

 respectively. 38. Conclusion. 



