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March 30, 1912
Detective Burns Listened
to Dynamiter Plots
Instruments That Can be Used for Eavesdropping
or for Business Purposes
It has been the impression of the public that the dictograph is a very complicated mechanism for automatically and unerringly recording the conversation carried on near it. In general, the mechanism employed is quite simple and easily understood. In fact there is no new principle involved. The invention is an adaptation of well-known apparatus to a peculiar purpose or situation.
The instruments are of three general types. First is the type shown in Fig. 1, sometimes modified as shown in Fig. 2. This is the type of apparatus referred to by Detective Burns in his dynamiting cases. It is really nothing more than a simple telephone circuit arranged to convey sounds from the talking station shown on the left to the listening or recording station on the right. Sometimes the transmitter is mounted in an innocent-looking square or triangular box, divided into two compartments. Within one compartment is room enough for small size dry batteries and for storing the receiver when the apparatus is not in use or is being carried about from place to place; within the other is located the transmitter element.
One wall of this second compartment of the box is, in reality, a thin diaphragm, with which is connected the microphone or resistance-varying element, usually a sensitive granular carbon transmitter button or cup. The size of the box is quite immaterial, but it is evident that the larger the diaphragm, the greater is the area of the sound-wave acting upon the transmitter element, and hence the better and stronger the reproduction of the sound at the receiving end of the line.
This is the type of instrument said to have been used by the famous Detective Burns and his associates in the MacNamara case and the so-called Lorimer-Hines bribery case. In each case the method of operating the device was somewhat as follows: Burns or any of his associated preventives “rigged up” a few rooms in a hotel. Appointments were made with suspects and accomplices. In one room in which the conversation or consultation was held, there was located the little transmitters disposed in a convenient but inconspicuous position; in the adjoining room the receiver of the instrument was placed, and an expert stenographer with the receiver to his ear took down the conversation carried on by the preventive and the suspect in the other room. Thus, it is declared, very valuable evidence was gathered. Indeed the success of the case is said to have depended upon the use of this ingenious device.
The use of this form of apparatus with slight modification has been applied to large auditoriums and churches. Instead of using a single transmitter and a single receiver, as shown in the figure, a number of transmitters
placed at various points about the stage or pulpit are arranged to gather the sounds and transmit to persons at remote parts of the hall the voices of the speakers or the strains of the orchestra. As many receivers as may be required are connected into the circuit to reproduce the sound at the remote points.
A somewhat similar apparatus is employed for announcing trains in the waiting rooms of large railway stations. The train announcer speaks into a transmitter and the sound waves are electrically reproduced by means of loud-speaking telephone receivers placed at various points about the great hall or waiting room. It is remarkable how clearly the voice is transmitted, for the announcement can be clearly and distinctly heard in every part of the immense room reverberating sonorously amid the huge marble pillars.
In a modified form, as shown in Fig. 2, the apparatus is employed in large business offices between a manager’s desk or office in one room and a stenographer’s desk in another room for the purpose of expeditiously dictating letters and transmitting intelligence of any kind. In this case the apparatus is really nothing more than an intercommunicating telephone system, for speech can be transmitted in both directions. Various switches are employed for connecting the apparatus of any one of a number of stenographers’ desks with the manager’s instrument.
The second broad class is shown diagrammatically in Fig. 3. This is an arrangement combining the use of the telephone and phonograph. This type of instrument is often known as the “telephonograph,” and in practice it assumes a number of different forms. In each case the principle is the same as that outlined in the figure. As soon as the telephone and the phonograph were invented the combined use of the two instruments suggested itself to a number of inventors. As early as February 1889, there were public exhibitions of such use of the two instruments in combination.
In a lecture before the Franklin Institute at Philadelphia, Mr. William J. Hammer performed the following experiment: A phonograph at New York was set to talk into a carbon transmitter, sending current waves over a telephone line to Philadelphia, a distance of 103 miles to the audience at the Franklin Institute. At that station a loud-speaking receiver talked into another phonograph and then in turn delivered to the amazed audience the tones of the original speaker in New York City.
No great practical use has been found for this combined instrument due to the great difficulty of keeping a suitable surface constantly in motion ready to record the sound waves. Furthermore much of the apparatus is too large and cumbersome to be conveniently portable, due largely to the size and weight of the motor mechanism for driving the cylinders.
It was early proposed to apply this instrument to the ordinary telephone to keep a record of the conversations passing over the line. This was to be especially useful in keeping a record of these conversations for subsequent use in legal controversies. It would be too easy, however, to manufacture such a record. At present an application of such device is found in some systems of telephone exchanges.
A continuously operating phonograph is used as a “busy-test.” If the subscriber calls a busy line he is automatically connected at the central station with this phonograph which continuously repeats the well-known ditty, “the line is busy, please call again.”
Another use of this type of instrument has been made in certain automatic fire-alarm installations. In this case thermostats are arranged to close a circuit at a predetermined temperature. This circuit controls the operation of a phonograph device, connecting it with the nearest telephone line. Arranged on the cylinder of this instrument is the message to be transmitted to the central station or to the nearest fire station. Such record may contain suitable words as “there is a fire at No. 99 Park Row.” The instrument is arranged first to signal central and then to repeat this message a number of times. “Central,” upon receiving such a message, connects the line directly with fire headquarters and thus, automatically an alarm is sent in almost instantaneously. With this arrangement, it is evident that a subscriber would be apprised of the fire call if he were using the telephone line and would immediately stop his conversation and hang up his receiver to allow the call to continue to “central.”
The third type of instrument is the dictating phonograph. This has nothing in common with the dictograph used by Detective Burns. The instrument consists of a strand or frame upon which is mounted a cylinder-bearing mechanism and a motor mechanism. By means of a foot-control, which is not clearly shown in the photograph, the motor (either spring or electrically driven) is started and stopped. The speaker sits at a table with his notes before him and speaks into an adjustable tube.
One of these instruments of the kind shown in Fig. 4 was used before the Senate Committee on Interstate Commerce. It was before this committee and recorded upon such a machine that George W. Perkins, many times a millionaire, and formerly business partner of J. Pierpont Morgan, and admitted to be a great authority on organized industry, made his remarkable statement that he had retired from business at the age of 48 because he was tired of making money and that he was devoting the rest of his life to a study of how to do good for the rest of mankind.
The machines as used are employed merely as an intermediate step between shorthand notes and a complete typewritten copy. Expert and highly paid stenographers took down in shorthand notes the name and the exact words of the speaker. These stenographers worked in shifts, each man taking stenographic notes for about an hour at a time. He would then take his written notes to an adjoining room and read them slowly and distinctly into the dictograph instrument, fresh cylinders being supplied whenever needed. By this means a very clear and uniform dictation resulted. A typist took this prepared cylinder to a similar machine arranged to reproduce the sound and transcribed at her leisure the words of the original speaker. By this means a great deal of time was saved since the transcribing could be done by a number of typists. The witnesses called before the committee at 10:30 were thus enabled late in the afternoon to read and correct the original testimony, and each day’s work was thus made complete in itself.