How did the circuits of early electric telegraphy look like? Was it just one big electric curcuit with different stations in it? If one of the stations connected to the network wanted to send a message to a certain other one, did all the other stations, although they were not adressee, receive the same message? And how did they solve the problem of one single message tying up the entire system before the invention of multiplex telegraphy?
Well, according to my copy of “Twentieth Century Manual of Railway Commercial and Wireless Telegraphy”, by Frederic L. Meyer (1914 edition), there were a variety of procedures used. Large cities had huge telegraph offices – 880 operators in the case of Western Union’s main Chicago office – connected to hundreds of lines. In this case, most of the operators were connected to each other through a manual switchboard, similar to a telephone setup, where they plugged their wire into the proper location to hook up with the other office. Many operators had set routines where they exchanged messages with specific locations at specific times over dedicated lines.
In outlying offices, say along a train route, there was often only one shared line, which could only be used for two-way communication by one pair of operators at a time, so the other operators had to wait their turn and make sure the line was clear before trying to use it. Each office and operator had call signs, so when you wanted to contact someone, you would tap out a message on the line naming the office you wished to contact, and then wait for it to respond. (Everyone along the line heard all of the traffic going on it).
A sample given in the book, with office “DX” calling office “DS” over a shared line, has the operator at DX sending:
DS DS DS DX DS DS DS DX DS DS DS DX
and the operator at DS responding:
I I DS
at this point the two operators would communicate how many messages would be sent, etc. It was considered bad form, except in the case of emergency, for another operator to break into the exchange of messages once it began – “contention for circuit is forbidden. Drumming or fooling on the wire is positively forbidden”. Presumably the offices along a shared lines also had rules about not hogging the line, and letting other people have a chance to send their own messages.
In some cases general messages were transmitted for all the operators down the line. (There is an interesting report of a musical concert being transmitted in 1876 during off hours to the operators along telegraph lines included in Telephonic Reminiscences, starting at the eighth paragraph).
Also, Telegraph Talk and Talkers has an overview of some of the day-to-day activites of a telegraph operator circa 1902.
Were the operators doing only the Morse job on the wire and nothing else? I believe in smaller offices, the operator also did the service for the clients at the counter. But then again, he would have had to leave the wire for a certain timespan during which he could miss a message for his station. Were there always two employees (one wire operator, one standing at the counter) even in small stations?
And: When sitting at the wire for hours, doesn’t his capability to pay attention decrease after a while, leading to mistakes when receiving messages?
Were the operators doing only the Morse job on the wire and nothing else? I believe in smaller offices, the operator also did the service for the clients at the counter. But then again, he would have had to leave the wire for a certain timespan during which he could miss a message for his station. Were there always two employees (one wire operator, one standing at the counter) even in small stations?
And: When sitting at the wire for hours, doesn’t his capability to pay attention decrease after a while, leading to mistakes when receiving messages?
No, in small stations you’d only have one operator, who sometimes also sold tickets, etc. Many small offices even closed at nights and on weekends. (There were also junior operators who travelled up and down the rail line to fill in as assigned).
The telegraph clicks were pretty loud – you could even get sounders that amplified the sound – so you could listen to the traffic as you did other duties, much like listening to a scanner today. If someone tried to contact you and you couldn’t respond immediately, you just noted their call sign and got back to them later. Or, if you were completely out of the office – and you were generally supposed to notify the other operators if you were going to be out, so it wouldn’t come as a surprise – the the sender would just retry later.
When messages can not be Promptly Transmitted
When for any reason an operator can not raise another office, or when wires are impracticable during stormy weather, an operator must note the cause of the delay upon the back of the message. When delayed owing to an inability to raise another office, mark the time on the back as you call him every few minutes
Yes, but no more than any other job. Remember, in most cases you were engaged in two-way communication, so all you had to do is ask the other operator to slow down and repeat anything you missed. (It was standard procedure to pause at regular intervals to check that your transmissions were getting through). Telegraphers were skilled professionals who took the need for accuracy very seriously, so this would have been seen as a reasonable request.