You can read a transcript of the first conversations on the transatlantic telegraph[1]. Basically: the signal was very weak, they needed a lot of time between s

You can read a transcript of the first conversations on the transatlantic telegraph[1]. Basically: the signal was very weak, they needed a lot of time between symbols, and they needed to repeat a lot. https://www.google.com/books/edition/Report_of_the_Joint_Committee_Appointed/76HmAAAAMAAJ?hl=en&gbpv=1&pg=PA232&printsec=frontcover https://www.google.com/books/edition/Report_of_the_Joint_Com...