VIII CONTENTS. 



Chatter II. Later and Final Stages in the Efficiency of the Fog Cham- 

 ber due to a Gradual Increase in the Bore of the Exhaust Pipes. 



CONNECTING PIPES NOT LARGER THAN 1. 5 INCHES IN DIAMETER. 



Page. 



35. Introductory 34 



36. Examples of data for i-inch connecting pipes 35 



37. Data for pipes i^ inches in diameter 35 



38. The same, continued. Shorter pipes 38 



CONNECTING PIPES 2 INCHES IN DIAMETER. 



39. Remarks on the method 41 



40. Data for pipes 2 inches in diameter, 12 inches long 42 



41. The same, continued. X-ray bulb inclosed in lead 44 



42. Discussion 45 



43. Radiant fields 49 



COLLOIDAL NUCLEI IN DUST-FREE AIR. EXHAUSTION PIPES AND STOP- 

 COCKS 4 INCHES IN DIAMETER. 



44. Purpose 51 



45. Apparatus 51 



46. Exhaustion difficulties 53 



47. Same, continued. Case of air in fog chamber saturated with water vapor. . . 55 



48. Case of saturated air in both chambers 59 



49. Observations with 4-inch exhaust pipes 65 



50. Observations, continued 70 



5 1 . The same, continued 71 



52. Discussion 73 



53. Summary 73 



Chapter III. Miscellaneous Experiments. 



54. Objects 77 



55. Growth of persistent nuclei 77 



56. Water nuclei produced by evaporation 78 



57. Distance effects. X-rays 82 



58. The same, continued. Small wood fog chamber 85 



59. The same, continued. Large wood fog chamber 85 



60. The same, continued. Discussion 86 



61. Distance effect and absorption. Radium 89 



62. Falling to pieces of ions in the lapse of time 91 



63. Decay curve 95 



64. The same, continued 97 



65. Condensation phenomena of the inclosed steam jet. Methods and results. . . 98 



66. Summary 102 



Chapter IV. Distribution of Colloidal Nuclei and of Ions in Media 



other than Air-water. 



COLLOIDAL NUCLEI AND IONS IN WET DUST-FREE CARBON DIOXIDE AND IN 



WET COAL-GAS. 



67. Apparatus 105 



68. Data for carbon dioxide 105 



69. Behavior of carbon dioxide 107 



70. Cause of differences 107 



