. The practical telephone handbook and guide to the telephonic exchange . 49a, which gives a view of a subscribers section of the Holborn(London) switch-board. This board is shown fitted for4600 subscribers lines. The positions of the keys, lamps, etc.,are clearly shown. The subscribers multiple jacks are fitted above the out-going-junction jacks in strips of 20, 5 strips being groupedtogether so as to give sets of 100, which are separated fromother sets by thin strips of white wood. All such sets of 100are numbered from 0 to 99, and each set is numbered by awhite number painted on a blac
. The practical telephone handbook and guide to the telephonic exchange . 49a, which gives a view of a subscribers section of the Holborn(London) switch-board. This board is shown fitted for4600 subscribers lines. The positions of the keys, lamps, etc.,are clearly shown. The subscribers multiple jacks are fitted above the out-going-junction jacks in strips of 20, 5 strips being groupedtogether so as to give sets of 100, which are separated fromother sets by thin strips of white wood. All such sets of 100are numbered from 0 to 99, and each set is numbered by awhite number painted on a black number-style stripfitted on the left-hand side of each set. The first of such sets(which usually commences on the left of each section on the 230 PRACTICAL TELEPHONE HANDBOOK lowest multiple row) is numbered 0, for numbers rangingfrom 0 to 99. The next set to the right is numbered 1, and isfor lines numbered from 100 to 199. The third set is numbered2, for numbers from 200 to 299, and so on to the ninth set,which is numbered 8, for 800 to 899. The tenth set is fitted. Fig 250.—Subscribers Section over the 0 set, and numbered 9, thus commencing another rowof hundreds, numbered from 9 to 17, the latter being fittedover the ninth set, numbered 8, and so on, building upwarduntil the full number of subscribers has been provided for. It might at first sight have been thought more convenientto fit the subscribers multiple-jacks in a lower position in COMMON BATTERY MULTIPLE SWITCH-BOARDS 231 the panels, but as some 80 per cent, of the calls in London arefor subscribers in other central offices, it is clearly of moreimportance in London to have the junction-line jacks in themore convenient position. For the same reason, it has beenfound advantageous to multiple the outgoing junction-linejacks more frequently than the subscribers jacks, so thatin the exchange in question they are multipled every 6panels instead of every 9. This enables junction lines to bevery easily and rapidly rea
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
