The observation included the opening of letters addressed to the accused, which were traced and the tracings filed before delivery of the originals to Ernst. There were included among these letters a large number of communications from Germany, chiefly from Potsdam, and Ernst himself sent many communications to Potsdam and Berlin. His letters were posted in different districts of London, while the letters coming from Germany to him were written on English note-paper and enclosed in English envelopes, which the prisoner had forwarded to Steinhauer for use--in one instance the paper and envelopes had been sent as "samples," the package being so weighty that Steinhauer had to pay excess postage at the other end. By opening both outgoing and incoming correspondence the authorities were placed in possession of a mass of valuable information as regards not only Ernst, but also other members of the system in England. For the purpose of the correspondence with Ernst, Steinhauer was alleged to have adopted the alias of "Mrs Reimers," and Ernst himself, the prosecution stated, changed his name from time to time, having letters addressed to his shop as to "J. Walters, care of K.G. Ernst," and sometimes to "W. Weller." These two names were the prisoner's own suggestion to Steinhauer. The latter sent letters not only to Ernst himself, but also missives to be forwarded to various places, including Chatham, Sheerness, and Portland Harbour. These letters were opened by the authorities under powers which they possessed for dealing with such cases, and tracings were taken before the letters were delivered. Ernst was requested by Steinhauer to find out all that he could about certain persons named, on the ground that they were connected or believed to be connected with the Intelligence Department of the War Office. One of the firms upon which he was called to make inquiries and report had an office in the City opposite to the office occupied by the late Captain Stewart, who figured in the German courts in an espionage case, and subsequently was imprisoned in a German fortress. In one of the envelopes sent to Ernst by Steinhauer were two letters, one of which was addressed to a British sailor, and the other to a German located at Portland Harbour. Further, the prosecution alleged, Ernst was in constant communication with persons named Kruger and Krumer, in connection with espionage work, while one of his letters referred to a magazine article which described the defences of the East Coast. Another letter contained reference to the espionage case against Parrott, which took place in the autumn of 1912. After January of 1914, Steinhauer requested Ernst to make inquiries about a person living in Somerset, and to this Ernst replied that he could not spare the time to do so, though he had previously gone up to Sheffield on business of a similar nature.