CHRISTCHURCH TELEPHONE EXCHANGE.

Globe, Volume XXIII, Issue 2334, 26 September 1881, Page 3

CHRISTCHURCH TELEPHONE EXCHANGE.

On Saturday last, September 24th, the subscribers in Ohristchuroh to the first Telephone Exohange established in this colony were notified that all necessary arrangements had been oomplefel, and that they were from that time telephonically in connection with eaoh other. Business at once commenced, and, allowing for a few mistakes, the result of inexperience, the maohinery was found to give with certainty and accuraoy all the results promised by the projeotor of the soheme. Dr. Lemon, Superintendent of Telegraphs, who, besides being an enthusiastic and talented practical electrician, is keenly interested in the progress and commercial sucoess of his department, was fully alive from the first to the business advantages to be gained from the invention of the telephone, and lent his assistance and enoouragement to those who desired to make use of it as a means of communication for their own separate convenience, and so far the system has been very extensively adopted in that manner. And, in order to extend its benefits to the utmost, he lost no time in arranging a scheme for establishing exohanges in the principal oentres of the colony, of which Christohuroh, by the ready response and enterprise of her business men, has the honor to be the first to make a beginning. The Telephonic Exchange, is an arrangement by which each contributor of a moderate sum is supplied with a separate wire from a point chosen by himself to a centre, at present a room attached to the telegraph office, a set of instruments and a battery, all of whioh are regulated and kept in order by the department. The wires are carried through the streets on poles put up for this special purpose, an arrangement which is neoessary, because it is found that when a wire is stretched side by side with telegraphic wires, the former picks up, in a more or less distinct manner, all the sounds made by the instruments used in transmitting messages by those wires, so that the effect in a busy circuit is to drown, by a multitude of confused sounds, the voioe of the speaker by telephone. As to this, Dr. Lemon, in a circular of instructions which is supplied to operators, says, ''The sound of dots and dashes " (produced by striking on the anvil of the Morse telegraph key) " is not got rid of. Investigations are, however, being made with a view of eliminating or neutralising them as much as possible, though it is but fair to state that hopes of overcoming the difficulty are but; faint." It will, on consideration, be seen that this difficulty is a most important one, as to avoid it the expense is made very much greater than would be the oase could the wires be attaohed to poles already in use for telegraph wires. The instruments supplied to the subscribers are a call box, a transmitter, a receiver, and a battery. On a card attached to the apparatus by the makers—the Western Manufacturing Company, Chicago—it is named the " Edison' telephone. As a matter of fact, however, there is nothing at all of Edison about it- The transmitter is by Blake, the receiver is by Bell, the contents of the call box are the inventions of many inventors, and the arrangement of the several parts, together with several important improvements and simplifications, are by Dr. Lemon. Amoagst the latter is the receiver, whioh, as sent by the makers, consisted of a formidable-looking apparatus, with two oases containing diaphragms to apply to the ear, whioh were to be attached by a sort of visor to the head of the operator. As improved, there is only one light ebonite frame about the size of a watch, which is to bo held to the ear. It contains an exceedingly thin plate of metal, and jit is by the vibrations of this diso that the sounds from the distant speaker are conveyed to the ear. The transmitter is a square box, containing in a convenient form a similar diaphragm, and, fixed at a proper height by the side of the other maohinery, is spoken into by the person conversing. The construction of the two parts just named, the transmitter and the reoeiver, are in a small compass, really wonders of science. A technical description of them would be out of place here; it is sufficient to say however that they form the exquisitely simple solution of a problem upon which the mightiest intellects of the world have exercised themselves. The call box is a greatly improved old acquaintance. The writer of this notioe saw it in full operation in Boston, U.S., twenty-six years ago, where, for fire alarm purposes, it had then been in use a considerable time. Its function is merely to communicate between the central office and the subscribers'|instruments. It is in faot a " communicator" suoh as may be seen in many of our hotels. The only difference is that a orank is turned instead of pressing a button. The battery supplied is a four cell "Le Clanch," it rings a bell at the central offioe, through the bell attaohed to the call box, whioh is sounded at the same time. There is a hook at the lower part of the call box, termed a "stirrup;" the receiver, when the telephone is at rest, is suspended from this stirrup, and then the bell only is ia circuit. The aot of removing the reoeiver from the stirrup outs out the bell and places the telephone ready for conversation. At the central office, the whole of the wires employed in the combination are brought to a cabinet in size about six feet long by two feet in breadth. Its face resembles somewhat the front of a totalisator, though much smaller. Fixed at the side are instruments corresponding to those at the termini, exoept that instead of a orank, a Morse key is used for the bell work. On the upper part of the cabinet is a faoe plate with rows of flaps, whioh oover numbers, in this case from 1 to 50. These flaps are worked by electro-magnets at the back of the plate. Under the number plate are a series of holes in insulated metallic bosses, numbered to correspond with the flaps above. These are also in connection with the wires at the termini. There are pairs of pegs connected by flexible insulated wires, whioh when inserted in any of the holes, conneot the wires they represent. It is the business of the operator who attends this machine to nse these pegs, as requested by his correspondents. He simply joins any two wires when direoted just as two Bpeaking tubes might be joined in the centre. To seoure this end there are many complex and beautiful operations performed by the machinery he has under his charge, but it is so arranged as to do most of the work automatically. The instruments are, as has been said, of American manufacture, and contrary to what is usually found in this particular class of goods, are of excellent workmanship. Great improvements, however, have been effected by Dr. Lemon in this part of the machinery also. The arrangements originally were suoh as notwithstanding the fact that fifty wires—that is, of course, twenty-five pairs of correspondents—could be _ brought through the instrument, only five pairs could speak at one time. And to effect this no fewer than fifteen different motions of the operator would have been neoessary. As it has left the hands of the improver its full capacity can be utilised—that is, twentyfive conversations can be carried on at the same time. Also, and not least, the maohine was Bent out with all its inner works exposed, it resembled, indeed, in that respect a watoh without a case. It has been cased in, and presents a neat handsome appearanse, while all its delicate parts are proteoted from dust or the interference of curious onlookers. The room itself in which the apparatus is kept is a marvel of neatness; with its multitude of wires disposed with mathematical accuracy around the walls, the numberless glittering braßS studs, Becured.by blue steel screws to polished codar or jet black ebonite, it is a sight well worth a visit to see, and reflects great credit on Mr Meddings and his staff for the pains that have been taken in its fitting up. The mode of operation is simplicity itself. A card oontains the names of the members who form the exohange, against whioh numbers are placed. Thus No. 1, wishing to speak to No. 2, would first turn the crank of his box —it should be two or three rather Bharp turns ; there is a toothed conical wheel attaohed to the crank, which, engaging another toothed wheel, slips down when turned, and pressing together metal springs brings the battery into play, and, as said before, rings the bell at the central office, and uncovers his number, ringing the ball on the call box at tho same time. This done, the operator would lift the receiver from the stirrup and apply it to his ear. The operator in charge at the centre would ask what was required : the number wanted being given, the reply would be, King him up. The pegs would be placed in tho holes bearing the numbers 1 and 2 on the instrument at the oentral offioe, No. 1 replaohag his receiver on the , stirrup, and going through the same motions would call and converse with No. 2. When communication is got with No. 2, his number also is uncovered at the central office. After it is seen there that both are in communication the flaps are

carefully replaced. When the conversation is ended the receivers are hung upon the stirrups, down drop the flaps before their numbers, whioh is a signal to the central operator. He takes out the pegs, covers up the numbers, and all is ready for a fresh start. Of course, should a correspondent inquire for another who is at the moment engaged, he is informed of the fact by the central operator, and told to call again in a few minutes. With a sharp hand at the central office, and a little experience gained by the other operators, it is possible to carry on the business with remarkable oelerity and with the most satisfactory results. The operator should speak into the transmitter in not loud but clear tones, articulating his words as perfectly as may be. It should be scaroely necessary to advise contributors not to meddle with the apparatus ; any hitch will speedily be remedied by competent workmen from the head office.

There are now about thirty subscribers to start with, and no doubt, as the advantages of the system are realised, that number will be greatly increased. Dr. Lemon is about to open a similar combination at Auckland, and afterwards one at Dunedin.