overall: 1 1/2 in x 3 in x 6 in; 3.81 cm x 7.62 cm x 15.24 cm
Telegraph keys are electrical on-off switches used to send messages in Morse code. The message travels as a series of electrical pulses through a wire. The operator pushes the key’s lever down briefly to make a short signal, a dot, or holds the lever down for a moment to make a slightly longer signal, a dash. The sequence of dots and dashes represent letters and numbers. This key is an example of the earliest type of key used by Samuel Morse and Alfred Vail.