The item presented here is a classic Morse system telegraph, which was equipped with a device for printing characters consisting of dots and dashes on a paper tape. The transmitting part of the device is a “telegraph key”, which was essentially a simple electric switch. As the operator presses the key lever, he or she transmits longer or shorter electric pulses that make up Morse code characters to the telegraph line. These pulses activate the electromagnet of the receiving part connected to the other end of the transmission line, causing a metal element to be attracted towards it. The element presses the paper tape onto the writing wheel, which is covered in ink from a container. The steady movement of the tape is achieved by means of a wind-up spring-loaded mechanism, much like the one used in clocks.
The telegraph type presented here was developed by Samuel Morse – an American inventor and painter. The first line was established in 1844 between Washington DC and Baltimore. Although Morse’s invention was not the first to attempt the implementation of the telegraph concept, it had the advantages of a relatively simple design and a low cost of construction of the production line, which is why it soon became the standard.
This object was manufactured by the Państwowa Wytwórnia Aparatów Telegraficznych i Telefonicznych in Warsaw. The establishment was formed from the temporary workshops that arose after independence was regained in 1918. The enterprise manufactured telecommunications equipment for the purposes of state institutions. In 1931, after a merger with the Państwowa Wytwórnia Łączności, its name was changed to Państwowe Zakłady Tele- i Radiotechniczne.