Campaign Telegraph constituted with a receiver, built by Mouilleron in Paris, and the remaining parts (transmitter, compass, lightning rods, cartridge and box) built and adapted by Maximiliano Augusto Herrmann in Lisbon.This Campaign Telegraph works with the transmitter and receiver in Morse code. It is a small device for the time it was built (18x39x17 cm.) and preceded the telegraph that the same author made, which allowed him to claim nine different innovations that have to do with size, portability, effective operation and easier to use. Predated the telegraph patent in 31 years but there were already some notable innovations that Herrmann only comes to claim in the licensing application of 1897.Herrmann introduced great technical changes in Morse receivers, making it more simple and easier to regulate. These improvements in Morse devices were praised at the International Telegraphic Conference in 1865.The device was first presented at the Porto International Exhibition in 1865 and was described in the Annales Telégraphiques of Paris and in the Journal of Telegraphs of Spain. In 1865, given the success achieved with these innovations and given the large number of orders of the Directorate-General of the Portuguese Post Office, Herrmann set a workshop in Lisbon to build precision instruments.