Part 3

The Luminous or Magnetite Arc Lamp 74

Mercury Arc Rectifier for Magnetite Arc Lamps 77

Incandescent Lamp Developments, 1894–1904 78

The Moore Tube Light 79

The Osmium Lamp 82

The Gem Lamp 82

The Tantalum Lamp 84

Invention of the Tungsten Lamp 85

Drawn Tungsten Wire 87

The Quartz Mercury Vapor Arc Lamp 88

The Gas-Filled Tungsten Lamp 89

Types and Sizes of Tungsten Lamps Now Made 91

Standard Voltages 93

Cost of Incandescent Electric Light 93

Statistics Regarding the Present Demand for Lamps 94

Selected Bibliography 95

LIST OF ILLUSTRATIONS

PAGE

Portion of the Electrical Exhibit in the United States National Museum viii

Otto Von Guericke’s Electric Machine, 1650 2

Voltaic Pile, 1799 4

Faraday’s Dynamo, 1831 8

Pixii’s Dynamo, 1832 9

Daniell’s Cell, 1836 10

Grove’s Cell, 1838 11

Grove’s Incandescent Lamp, 1840 13

De Moleyns’ Incandescent Lamp, 1841 14

Wright’s Arc Lamp, 1845 15