LIST OF FIGURES. 



CHAPTER I. 



I'AGK 



Figure 1. Color tube. Sectional elevation. Scale about /g 3 



Figure 3. Diiferential color tube o 



Figure 3. Color tube with influx pi|)es 2 



Figure 4. Color tubes in series 2 



Figure 5. Steam box or separator 2 



Figure 6. Nozzle of steam jet. Scale | o 



Figures 7, 8. Charts, showing the margins of the opaque Held at dili'erent temperatures and jMcssures, 



for atmospheric air g 



Figure 9a. 9b. Phosphorus ionizers. Scale i fj 



Figure 10. Sensitive points, etc.. of the influx pipe j^ 



Figure 11. Apparatus for heating the emanation ^; 



Figures 13, 13, 15. Electrical (high potential) ionizers S 



Figure 14. Spiral brush t; 



Figures 16. 17. Completed electrical ionizers. Scale ^ H 



Figure 18. X-ray ionizer. Scale fV ^ j 



Figure 19. Apparatus for testing the persistence of nuclei. Scale J 11 



Figure 30. Long tubes (60 feet), for testing persistence. Scale y'j 11 



Figure 31. Ultra-violet ionizer. Scale i H 



CHAPTER 11. 



Figure 1. Gasometer train and color tube. Scale y'j 17 



Figure 3. Influx pipe with ionizers in multiple. Scale } 17 



Figures 3. 4. Charts showing the relation of the relative number of particles (dust contents) to the color 



produced, expressed in thicknesses (air) of Newton's interference plates 33 



Figure 5. Chart showing margins of the opaque field in terms of air temperature and steam pressure. . 24 



Figure 6. Chart showing margins of the colored fields in terms of temperature and pressure 24 



Figure 7. Adjustable nozzle for steam jet. Scale i 29 



Figure 8. Gasometer train and modified color tube 29 



Figure 9. Tubular condenser for ionized gases 09 



Figure 10. Chart obtained with new jet corresponding to figures 3 and 4 31 



CHAPTER in. 



Figure 1. Color tube and absorption tube. Scale jV 3.3 



Figure 3. Diagram ;^t) 



Figure 3. Chart showing the relative number of particles (ordinates, <lnst-contents in liters per mimite) 



needed to produce full blue for different lengths (abscissas) and diameters of the ab.soi-ptiou tubes. 38 



CHAPTER IV. 



Figure 1 . Diagr.am of the condenser and the electrometer in parallel 43 



Figure 2. Sectional elevation of the condenser. Scale J 43 



Figure 3. Chart showing the ageing of the ionizer 47 



Figure 4. Chart showing the effect of temperature on the activity of the ionizer 47 



Figure 5. Fall of potential in the lapse of time for different distances of the condenser i)lates 47 



ix 



