115
83. Simple telephone connection 116
84. Telephone stations in circuit 117
85. Illustrating light contact points 118
86. The microphone 119
87. The transmitter 119
88. Complete telephone circuit 121
89. Device for making hydrogen and oxygen 124
90. Electric-water purifier 127
91. Portable electric purifier 129
92. Section of positive plate 130
93. Section of negative plate 130
94. Positive and negative in position 130
95. Form of the insulator 130
96. Simple electric heater 137
97. Side view of resistance device 139
98. Top view of resistance device 139
99. Plan view of electric iron 140
100. Section of electric iron 141
101. Thermo-electric couple 143
102. Cutting a magnetic field 146
103. Alternations, first position 148
104. Alternations, second position 148
105. Alternations, third position 148
106. Alternations, fourth position 148
107. Increasing alternations, first view 149
108. Increasing alternations, second view 149
109. Connection of alternating dynamo armature 150
110. Direct current dynamo 151
111. Circuit wires in direct current dynamo 152
112. Alternating polarity lines 154
113. Alternating current dynamo 155
114. Choking coil 157
115. A transformer 158
116. Parallel carbons 164
117. Arc-lighting circuit 165
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