Part 9 (1/2)
The switchboards themselves are made of hard, black rubber, and are honeycombed with innumerable holes, each of which is connected with a subscriber. Below the switchboard is a broad shelf in which are set the miniature lamps and from which project the bra.s.s plugs in rows. The flexible cords containing the connecting wires are weighted and hang below, so that when a plug is pulled out of a socket and dropped it slides back automatically to its proper place, ready for use.
Many subscribers nowadays have their own private exchanges and several lines running to central. Perhaps No. 4341 Eighteenth Street, for instance, has 4342 and 4344 as well. This is indicated on the switchboard by a line of red or white drawn under the three switch-holes, so that central, finding one line busy, may be able to make connection with one of the other two, the line underneath showing at a glance which numbers belong to that particular subscriber.
If a subscriber is away temporarily, a plug of one colour is inserted in his socket, or if he is behind in his payments to the company a plug of another colour is put in, and if the service to his house is discontinued still another plug notifies the operator of the fact, and it remains there until that number is a.s.signed to a new subscriber.
The operators sit before the switchboard in high swivel chairs in a long row, with their backs to the centre of the room.
From the rear it looks as if they were weaving some intricate fabric that unravels as fast as it is woven. Their hands move almost faster than the eye can follow, and the patterns made by the criss-crossed cords of the connecting plugs are constantly changing, varying from minute to minute as the colours in a kaleido-scope form new designs with every turn of the handle.
Into the exchange pour all the throbbing messages of a great city.
Business propositions, political deals, scientific talks, and words of comfort to the troubled, cross and recross each other over the black switchboard. The wonder is that each message reaches the ear it was meant for, and that all complications, no matter how knotty, are immediately unravelled.
In the cities the telephone is a necessity. Business engagements are made and contracts consummated; brokers keep in touch with their a.s.sociates on the floors of the exchanges; the patrolmen of the police force keep their chief informed of their movements and the state of the districts under their care; alarms of fire are telephoned to the fire-engine houses, and calls for ambulances bring the swift wagons on their errands of mercy; even wreckers telephone to their divers on the bottom of the bay, and undulating electrical messages travel to the tops of towering sky-sc.r.a.pers.
[Ill.u.s.tration: A FEW TELEPHONE TRUNK WIRES This shows a small section of a complicated telephone switchboard.]
In Europe it is possible to hear the latest opera by paying a small fee and putting a receiver to your ear, and so also may lazy people and invalids hear the latest news without getting out of bed.
The farmers of the West and in eastern States, too, have learned to use the barbed wire that fences off their fields as a means of communicating with one another and with distant parts of their own property.
Mr. Pupin has invented an apparatus by which he hopes to greatly extend the distance over which men may talk, and it has even been suggested that Uncle Sam and John Bull may in the future swap stories over a transatlantic telephone line.
The marvels accomplished suggest the possible marvels to come.
Automatic exchanges, whereby the central telephone operator is done away with, is one of the things that inventors are now at work on.
The one thing that prevents an unlimited use of the telephone is the expensive wires and the still more expensive work of putting them underground or stringing them overhead. So the capping of the climax of the wonders of the telephone would be wireless telephony, each instrument being so attuned that the undulations would respond only to the corresponding instrument. This is one of the problems that inventors are even now working upon, and it may be that wireless telephones will be in actual operation not many years after this appears in print.
A MACHINE THAT THINKS
A Typesetting Machine That Makes Mathematical Calculations
For many years it was thought impossible to find a short cut from author's ma.n.u.script to printing press--that is, to subst.i.tute a machine for the skilled hands that set the type from which a book or magazine is printed. Inventors have worked at this problem, and a number have solved it in various ways. To one who has seen the slow work of hand typesetting as the compositor builds up a long column of metal piece by piece, letter by letter, picking up each character from its allotted s.p.a.ce in the case and placing it in its proper order and position, and then realises that much of the printed matter he sees is so produced, the wonder is how the enormous amount of it is ever accomplished.
In a page of this size there are more than a thousand separate pieces of type, which, if set by hand, would have to be taken one by one and placed in the compositor's ”stick”; then when the line is nearly set it would have to be s.p.a.ced out, or ”justified,” to fill out the line exactly. Then when the compositor's ”stick” is full, or two and a half inches have been set, the type has to be taken out and placed in a long channel, or ”galley.” Each of these three operations requires considerable time and close application, and with each change there is the possibility of error. It is a long, expensive process.
A perfect typesetting machine should take the place of the hand compositor, setting the type letter by letter automatically in proper order at a maximum speed and with a minimum chance of error.
These three steps of hand composition, slow, expensive, open to many chances of mistake, have been covered at one stride at five times the speed, at one-third the cost, and much more accurately by a machine invented by Mr. Tolbert Lanston.
The operator of the Lanston machine sits at a keyboard, much like a typewriter in appearance, containing every character in common use (225 in all), and at a speed limited only by his dexterity he plays on the keys exactly as a typewriter works his machine. This is the sum total of human effort expended. The machine does all the rest of the work; makes the calculations and delivers the product in clean, s.h.i.+ning new type, each piece perfect, each in its place, each line of exactly the right length, and each s.p.a.ce between the words mathematically equal--absolutely ”justified.” It is practically hand composition with the human possibility of error, of weariness, of inattention, of ignorance, eliminated, and all accomplished with a celerity that is astonis.h.i.+ng.
[Ill.u.s.tration: THE LANSTON TYPE-SETTER KEYBOARD As each key is pressed a corresponding perforation is made in the roll of paper shown at the top of the machine. Each perforation stands for a character or a s.p.a.ce.]
This machine is a type-casting machine as well as a typesetter. It casts the type (individual characters) it sets, perfect in face and body, capable of being used in hand composition or put to press directly from the machine and printed from.
As each piece of type is separate, alterations are easily made. The type for correction, which the machine itself casts for the purpose--a lot of a's, b's, etc.--is simply subst.i.tuted for the words misspelled or incorrectly used, as in hand composition.
The Lanston machine is composed of two parts, the keyboard and the casting-setting machine. The keyboard part may be placed wherever convenient, away from noise or anything that is likely to distract or interrupt the operator, and the perforated roll of paper produced by it (which governs the setting machine) may be taken away as fast as it is finished. In the setting-casting machine is located the brains. The five-inch roll of paper, perforated by the keyboard machine (a hole for every letter), gives the signal by means of compressed air to the mechanism that puts the matrix (or type mould) in position and casts the type letter by letter, each character following the proper sequence as marked by the perforations of the paper ribbon. By means of an indicator scale on the keyboard the operator can tell how many s.p.a.ces there are between the words of the line and the remaining s.p.a.ce to be filled out to make the line the proper width. This information is marked by perforations on the paper ribbon by the pressure of two keys, and when the ribbon is transferred to the casting machine these s.p.a.ce perforations so govern the casting that the line of type delivered at the ”galley” complete shall be of exactly the proper length, and the s.p.a.ces between the words be equal to the infinitesimal fraction of an inch.