CONTENTS 
‘Records and Results 
55. The field record 
56. The permanent record 
57. Sums and means 
58. Curves 
Humidity 
59. Instruments 
Psychrometers 
60. Kinds 
61. The sling pavehronikier 
62. Readings : ; 
63. Cog psychrometer 
64. Construction and use 
‘65. Hygrometers 
Psychrographs 
' 66. The Draper psychrograph 
67. Placing the instrument 
68. Regulating and operating the instrament 
69. The weekly visit 
Humidity Readings and Records 
zo. The time of readings 
71. Place and height 
72. Check instruments 
73. Humidity tables 
74. Sums, means, and curves 
Conversion scale for temperatures 
75. Records 
Light 
76. Methods 
The Photometer 
77. Construction 
78. Filling the plictombiee 
79. Making readings 
80.. The Dawson-Lander sun fecevler 
81. The selagraph 
Standards 
82. Use ; 
83. Making a standard 
84. Kinds of standards | 
Readings _ 
85. Time 
Chart for aeceinine sun’s aide 
vii 
