Bank of 50 Keith Line Switches recovered from a rural exchange in New Zealand, made by the Automatic Electric Company, Chicago, 1920-1925. Together with spare plunger, two spare line backs, and two pre-2000 two-motion selectors

Bank of 50 Keith Line Switches recovered from a rural exchange in New Zealand, made by the Automatic Electric Company, Chicago, 1920-1925.

The line switch, devised by Alexander Keith of the Strowger Company in 1906, obviated the need for each user's line to be connected to a more expensive selector switch. The number of selector switches employed henceforth only needed to be sufficient to handle the maximum number of calls expected at any one time. This bank of line switches was part of the main telephone exchange in Wanganui, New Zealand, until the mid-1990s. Similar line switches were installed at Epsom and other trial automatic exchanges in Britain from 1912.