Electric Fire Alarm Apparatus and Parts Thereof; Police Electric Signalling and Telephone Apparatus; Electric Public Alarm Apparatus for Announcing Fire, Air Raid Warnings, and Other Emergencies; Electric Watchman's Console, Supervisory and Emergency Signalling Apparatus; Electric Auxiliary Fire Alarm and Police Signalling Apparatus; Electric Voice Communication and Amplifying Apparatus; Optical Smoke Detection Apparatus; Ionization Detection Apparatus; and Combination Optical and Ionization Smoke Detection Apparatus