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1892: |
The old annunciator at the Brooks House, which was on the French system now generally discarded, and which was injured by fire several years ago, has been replaced by a new gravity-drop system of the most approved kind. All the wires run upon the surface instead of in the walls as heretofore, and are brought into an annunciator of 100 drops. |
an·nun·ci·a·tor (ə-nŭn′sē-ā′tər)
n.
One that announces, especially an electrical signaling device used in hotels or offices to indicate the sources of calls on a switchboard.
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also
from the site you found:
“”gravity drop, in which a target is released by the action of the current, and its weight causes it to drop into view, thus indicating that a call has been made”