xii CONTENTS 



CHAPTER XII 



PAGE 



-MISSION OF POWER BY ALTERNATING CURRENT 377 



157. Transmission Systems 377 



158. Transmission Line Reactance; Single-phase 380 



159. Transmission Line Reactance; Three-phase 382 



160. Transmission Line Capacitance; Single-phase 383 



161. Transmission Line Capacitance; Three-phase 386 



162. Three-phase System; Conductors Spaced Unsymmetrically . 387 



163. Single-phase Line Calculations 387 



164. Three-phase Line Calculations 389 



165. Lines Having Considerable Capacitance 391 



166. Corona 393 



Lightning Arresters 395 



167. Multigap Arresters 395 



168. Horn Gaps 397 



169. The Aluminum Cell Arrester 398 



Transmission Line Construction 401 



170. Pin-type Insulators 401 



171. Suspension-type Insulators 402 



172. Transmission Structures 403 



Sub-stations 406 



173. Transformer Sub-stations 406 



174. Motor-generator and Synchronous-converter Sub-stations . . 407 



175. Oil Switches 408 



176. Arrangement of Apparatus in Sub-stations 410 



177. Automatic Sub-stations 411 



178. Outdoor Sub-stations 411 



CHAPTER XIII 



ILLUMINATION AND PHOTOMETRY 413 



179. Candlepower 413 



180. Unit Solid Angle or Steradian 414 



181. Luminous Flux: Lumen 414 



182. Illumination . 416 



183. Law of Inverse Squares 417 



184. Absorption; Brightness 418 



185. Light Distribution 419 



186. Light Sources; Incandescence; Luminescence 420 



187. Carbon-filament Lamp 420 



188. The Tantalum Lamp 421 



189. The Tungsten Type-A and Type-B Mazda Lamps 421 



190. Gas-filled Lamps; Type-C 423 



191. Effect of Voltage Variation on Incandescent Lamps 424 



192. Arc Lamps 425 



193. The Enclosed Arc . . 427 



