Fire alarms were originally raised by ringing church bells. Due to the nature of sound, bells had the huge disadvantage of being affected by environmental conditions, making finding the fire extremely difficult.
In 1845 American William Channing proposed using Samuel Morse's telegraph system to raise the alarm and coordinate a, response. His system comprised signal boxes that would send automated messages of their location (and hence the fire) to a central office. The fire-alarm signal-box system is still used in the United States and is akin to the manual "break-glass" fire call point more commonly used in Europe. In the central office an operator would forward the message to all other signal boxes within the circuit. At the same time electrical impulses would be sent to automatic bell strikers to sound the alarm and alert the firefighters, who at that time were mostly volunteers. By going to their nearest signal station, the firefighters could communicate with the central office and act appropriately.
Channing collaborated with Moses Farmer, a pioneer of electrical engineering, to bring his vision to life. In 1852, after convincing the mayor of Boston to trial their invention, the world's first system was installed. After initial hiccups, their system was eventually put into service in 1854, and a patent was issued in 1857, by which time their system had been installed in more than forty towns and cities.
Although improvements were made, the system remained largely unchanged until the advent of digital systems in the late twentieth century, but the principles of their design remain valid today.
