Telegraph Register
From the collection of National Museum of American History. Free to download, adapt and use — no permission needed.
In 1850 William S. Thomas received U. S. patent #7,092 for his “telegraphic register.” This model demonstrated his method of using the heat generated by an electric current to record Morse code signals. Thomas designed a system that electrically heated two platinum points. As the paper passed under them, the points would record the dots and dashes as a series of scorch marks. Also, an operator could see the points glow and fade as the current switched on and off, enabling them to read the message optically. His idea never gained acceptance as his system failed to convince operators to give up on recording Morse code messages with ink and listening for the sounds of the clicking electromagnets.
National Museum of American History’s own description
