These spiracles, according to Hinds, are remarkable honeycomb-like structures, and perforations to the tracheal tubes have not been demonstrated.
At the receiving station electrical mechanisms record the signals once more as perforations in a paper strip forming an exact replica of the transmitting tape.
This received perforated tape is then used to control what is known as the printer or automatic typewriter, a machine that translates the tape perforations into letters and prints the messages in Roman type in page form.
When there is no current the shutter covers the perforations and no light passes, but when a current traverses the wires they are depressed by electromagnetic action, carrying the shutter with them, and a quantity of light proportional to the current strength is admitted through the perforations.
The record of the signals given by this instrument was an undulating line of fine perforations or spots, and the character and succession of the undulations were used to interpret the signals desired to be sent.