It was customary up until the teens for fire alarm telegraph circuits mounted atop utility poles. The purpose was so that these important wires would not be physically and interfered with any other wires that might happen to physically touch them, thus causing electrical connection problems between the call box and nearest fire station. When paired telephone cable and electrical utility distribution circuits became more standardized (and a bit safer) commencing in the teens, new and upgraded lines saw fire alarm curcuits mounted lower along pole routes. This photo is from an edited Shorpy image.