Popular Science Monthly/Volume 70/April 1907/Notes on the Development of Telephone Service V
|NOTES ON THE DEVELOPMENT OF TELEPHONE SERVICE|
By FRED DE LAND
VIII. Subscribers' Pioneer Telephone Equipment
IN the previous chapter it was shown how the primitive telephone set supplied to subscribers by the New Haven and other pioneer exchanges consisted only of a mahogany or rubber magneto hand telephone hung on a steel hook screwed into 'wall or board, and how the use of the circuit-breaking push button was the approved method of calling central. No vibrating bell was supplied to the subscriber. When central called, attention was attracted with the aid of a buzzing, squealing noise, that was sent through the telephone by manually and rapidly operating a large induction coil attached to the switchboard. That was the method in vogue early in 1878, and, as already stated, in the beginning it was the custom to use this one-hand telephone as
transmitter and receiver, dexterously moving it from lips to ear and from ear to lips, as the conversation progressed. From time to time instructions were issued to subscribers on the proper use of the telephone. One of the first read: 'Do not talk with your ear, or listen with your mouth.' Where a subscriber was willing to pay for 'two telephones,' he enjoyed the unusual convenience of following the now common method of holding the receiver to his ear while talking into the transmitter, as shown in Fig. 22. Not many duplicate telephones were installed, but occasionally an editor would consider his time of sufficient value to justify the increased outlay of $10 a year for a 'second telephone.'
Following the now famous experiments with his telephones at the Centennial, Alexander Graham Bell had displaced the parchment or membrane diaphragm with one of iron, and brought out the wooden hand telephone to take the place of the oblong box, so inconvenient for general use. Then, in December, 1877, a few long rubber-encased hand telephones similar in form to the present receiver were sent out to several exchanges as an experiment. On July 1, 1878, Mr. Coy had 230 mahogany hand telephones, about 100 rubber hand telephones
and a dozen box telephones. But this rubber hand telephone did not go into general use until the summer of 1878, and, in some exchanges, never really supplanted the original wooden hand telephone, the earlier magneto sets doing so.
Meanwhile an improved form of the oblong box telephone, shown in a previous chapter, was brought out in June, 1877, but met with no favor, as it also required a table or a shelf for its support in a horizontal position. In August, 1877, came the first of the oblong box telephones remodeled so as to be fastened to the wall in a vertical position (Fig. 23). The only telephone circuits in those days were private and social lines, the first commercial exchange opening in January, 1878, and users of projected private lines did not take kindly to this innovation, preferring to have the more convenient hand telephone which could so easily be shifted from lips to ear. And this was the prevailing sentiment even after exchanges were in operation. Thus this upright form of box telephone did not come into general use until the winter of 1878-79, when it served only as part of a subscriber's set.
In the autumn of 1878, the parent Bell company brought out the first of the many forms of magneto bell telephone sets. This early type of wall set (Fig. 24) had the rubber-encased hand telephone hung from a hook projecting through the door on the front of the box. The attaching of two hand telephones to the magneto to serve as transmitter and receiver (Fig. 25) naturally followed. The introduction of this magneto ringing device displaced the circuit-breaking push-button method of calling central, and the single-stroke bell as part of the subscriber's equipment. It also enabled the local companies
|Fig. 24.||Fig. 25.|
to secure more equitable rates by increasing the rental where the new equipment was installed.
In the pioneer days when local rates ranged from $18 to $36 per year, nearly all the subscribers were on party-lines, and few lines carried less than twelve telephones. 'How many boxes are there on your line?' was a question often asked by subscribers in the days when it was not unusual to have twelve, or even twenty or more subscribers on a grounded iron-wire circuit in towns. In May, 1878, it was stated that one circuit had 'fifty-six instruments, and conversation is carried on with perfect ease.' Another town boasted of forty-three telephones on one line. Naturally there was more or less eavesdropping, with the usual entailed bitterness. Thus the parent company found it advisable to sanction the addition of a secrecy-switch to the magneto bells supplied by the different manufacturers. One form of this lock-out switch is shown on the front of the magneto box in Fig. 25. Removing the receiver or hand telephone from the box caused the latter to fly up, just as the hook on the side of the modern telephone does. If the subscriber desired to converse with some one on the line to the right of his telephone, he would turn the switch to the right, thus shutting out all subscribers to the left, but still leaving it possible for eavesdroppers on the right to listen in. If the switch was turned to the left, the subscribers to the right were cut out. To operate the bell it was only necessary to turn the crank at a moderate speed and at the same time to press the button underneath the box the number of times that corresponded with the number of rings required to call the given station.
The next change came in the adoption of the first of the vertical boxes as a transmitter in connection with the magneto-call bell, and the use of the hand telephone as a receiver. In method of operation both instruments were identical, either could be used as transmitter or receiver, and both were fastened to the wall side by side (Fig. 26). The approved method of calling then in vogue is also shown (Fig. 27). The circular of instructions sent out with this early wall set read:
By reason of its simplicity of operation, the 'push-button magneto' (Fig. 29) type of instrument was popular during its brief existence. In construction and operation it materially differed from the crank instrument. In the latter, the current followed the revolving of an armature within a magnetic field; in the former, the current was produced by pushing the button on the face of the instrument, thus 'forcibly detaching a soft iron armature from the poles of a permanent magnet surrounded with coils of insulated wire.' The following instructions were sent with this instrument in 1880:
Owing to the rapidity with which improvements and modifications in equipment appeared during the first five years, rarely did the subscribers in any two exchanges have the same type of instruments, the newer exchanges having the later types except where the most rigid economy was practised. Yet it often happened that when the patrons in one town learned that the subscribers in an adjoining town had a later type of instruments, the local owners were given no rest until up-to-date instruments were installed, even though the equipment declared to be antiquated and obsolete had been in use only from twelve to eighteen months.
Of course, the parent company, through its earnest efforts to afford the operating companies every serviceable improvement, was indirectly responsible for this unavoidable variance in subscriber-equipment. And while modifications in form and improvement in workmanship were not patentable, they were the result of careful and costly experiments in the course of which the parent company was 'obliged to withdraw from use and condemn many thousands of instruments, not because they were inoperative, but because others were better.' Transmitters and receivers were kept in good condition by the parent company, and replaced with new or improved types as often as necessary without expense to the local company. But the remainder of the equipment had to be purchased from such manufacturers as were able to supply it. Hence, to displace old with new equipment was often a costly change for the local company.
In commenting on the trouble caused by defective telephone cords, the Committee on Telephone Supplies reported at the fourth convention (1882) that
In 1883, Mr. C. N. Fay said:
In one way it was encouraging to the owners of the pioneer local plants to perceive how rapidly the list of subscribers increased. In another way this unexpectedly rapid growth was depressing in character, because it had not been anticipated and consequently the plant had not been constructed on corresponding lines. Where the investment was not of a speculative nature, but made on a permanent basis, the owners soon realized that they had not been just to themselves nor to the public in building so cheaply and so sparingly. Again, the funds necessary to meet these constantly changing conditions were not readily forthcoming, for not one in ten of the pioneer organizations earned dividends prior to 1882.
In 1880, the parent Bell company gave this sensible advice to its operating companies:
The parent company also stated that printed lists of subscribers should be prepared in 'form like a dancing programme.' Incidentally it may be added that current subscribers' directories in cities like Pittsburgh now weigh about three pounds each, while the directory used in New York City weighs nearly twice as much. The latter contains the names of more than three hundred thousand individuals or firms and about four hundred thousand copies of each issue are distributed. Owing to the frequent revision of Bell subscriber-lists these 'dancing-programmes' are admittedly the most reliable directories in the cities.
Although Graham Bell's hand telephone transmitted messages with remarkable clearness, even over long distances where no disturbing causes interfered, yet it did not possess sufficient power to satisfactorily serve under the varied conditions that developed as the scope of telephone service expanded in all directions. Even though there were no electric-light circuits and no trolley lines, the inductive effect and the zone of noise was always in evidence; for telegraph lines paralleled many telephone circuits and, as practically all lines were grounded, the effect of earth currents was often plainly perceptible. So sensitive was the telephone found to be, that scientists employed it in delicate researches to detect the flow of electrical currents so minute as to be inappreciable to all other instruments. And Graham Bell stated that in standing on a large board placed on his lawn, if a single spear of grass came in contact with his foot while experimenting with his telephone, the effect of ground currents was instantly perceptible, yet disappeared the moment the connection was broken between shoe and grass.