"Among other useful applications of the telegraph is the *fire alarm system.* In 1852 Channing and Farmer, of Boston, Mass, devised a system of telegraphic fire alarms, which was adopted in the city of Boston (U.S. Pat. No 17,355, May 19, 1857), and which in varying modifications has spread through all the cities of the world, introducing that most important element of time economy in the extinguishment of fires. Hundreds of cities and millions of dollars have thus been saved from destruction.
"Similar applications of local alarms in great numbers have been extended into various departments of life, such as *District Messenger Service,* *Burglar Alarms,* Railroad-Signal Systems,* *Hotel Annunciators,* and so on."
(((bruces remarks: It seems to me little appreciated that the telegraph as a species radiated into many specialized niches. Fire alarms and burglar alarms might be better described as "networks of sensors" rather than "media" per se, but these alarm systems were technically impossible before the telegraph, and their economic scope and influence on society must have been huge. I confess I have no idea what a "District Messenger Service" may have been. The deeply symbiotic relationship of railways and telegraphs is a subject worthy of close study. Dead forms of "hotel annunciator" still await the Necronaut who can resurrect this modest but intimate medium.)))
Paul Di Filippo (email@example.com)