be 3,000 miles. If the rate between "A" and "C" is 30 cents, the toll revenues represented will be one hundred times 30 cents or $30.00. If each company deducts 25 per cent. for originating the business, there will remain $22.50 toll tariff subject to to mileage division, and of this two-thirds should go to the credit of the company owning the line from "A" to "B," and one-third to the company owning the line from "B" to "C." Following out this plan of mileage calculation, the credit for each company on a month's business between all stations on one company's lines and all stations on the other company's lines can be included in one general settlement and the exact amount due each company on mileage easily ascertained. In arriving at mileage settlements between connecting toll line companies, each company should assume the mileage of its subsidiary connections and should make a division of its share of the new revenue with such connections.

In reference to the division of tariff between toll line companies and exchanges having no toll line mileage, it must be borne in mind that the toll line companies have their entire investment tied up in a system from which their sole revenue is toll business, and although exchanges at the termini of the toll line. may represent a much larger investment than is represented by the toll line, the investment in the exchange depends only in a small measure on the toll line business which is handled by the exchange, with very little additional investment. For instance, a toll message transmitted between two exchanges of 1,000 subscribers each, over a toll line having two circuits, involves the actual use for the time being of only one-thousandth part of the investment in the exchange, but at the same time, ties up one-half of the entire toll line system.

There can be no dispute as to the fairness of basing commissions paid to exchanges entirely on originating business for the reason that a large part of the expense incurred by the exchange in handling toll business arises from the necessity of making collections, and it seems reasonable that the exchange, which assumes this part of the transac

tion, should be entitled to a greater compensation than the exchange which merely delivers the message.

In making charges against and giving credit to various companies dividing toll revenue, the following method is used:

Charge each company with "tolls sent paid," tolls received collect," and "messenger fees collected." Give each company credit for "messenger fees paid," "commission on originating business and "mileage" (as shown by mileage statement). To get this information it is, of course, necessary for each company originating business to make a careful record of the business transacted with each station as follows:

"Number of messages sent," "number of messages received," "over-time,". "amount of tolls sent paid," "amount of tolls sent collect," "messenger fees collected," "tolls rceived paid," "tolls received collect," "messenger fees paid." So-called "deadhead messages" should be entirely eliminated and operators required to make a charge ticket for all messages, no matter by whom sent or for what purpose. A record can be made of company business subject to frank, and an adjustment of same made between companies interchanging business. Some contracts between large toll line companies specifically set forth that neither company shall carry free business for the other.

In many localities, a limited territory. is covered by a series of short connecting toll lines, each line owned separately and under separate management, and the division of joint revenue between such lines presents a problem more complicated than the division between large toll systems. In some instances, this problem has been solved by local joint traffic associations. The membership of the association is composed of representa-. tives of each of the connecting companies, the plan of revenue division being similar to that outlined in the present discussion. The formation of local associations should receive careful consideration and should be encouraged.

In Chautauqua County are nine short toll lines, extending from Jamestown via Sherman and Mayville to Westfield, and thence east and west from Westfield along the Lake Shore. Some time ago

these companies formed a traffic association for the purpose of establishing uniform rates and adopting a system for handling the business interchanged among themselves, as well as business to points outside their district. This association, known as the Independent Telephone Clearing Association, with its office at Sherman, receives a monthly report of the business transacted from each of the companies making up the association. The association employs a secretary, who makes a division of the revenue from the reports received, rendering each company a statement of its charges and credits. Remittances are made direct to the association secretary, who in turn makes remittances to those who have balances due them. The secretary's compensation is based on a certain amount for each message handled by him in the work of clearing the entire business, the amount being fixed at something like one-half cent a message.

The method of dividing revenue derived from business going to points on other lines outside of the association lines is as follows:

The association lines connect with the lines of the Inter-Ocean Telephone and Telegraph Company at Jamestown and with the Union Telephone and Telegraph Company at Corry, Pa. Each of these toll line companies renders a monthly statement to the association treating the entire group of lines as one toll line company. If the association

has a balance due it from toll line companies, it goes into the association fund for general distribution and is disbursed among association members, according to mileage furnished by each.

The local association has a great advantage in being able to come in close contact with its members and to know thoroughly the territory which is being covered. Switching fees are entirely eliminated in our interchange of toll business throughout the State, and should be entirely done away with, as their general adoption acts as a great handicap to the successful conduct of the toll business and gives competing interests a great advantage over the Independent toll line systems. There has been some discussion relative to the formation of a State traffic association for

the purpose of clearing interchanged business between the larger toll line companies. This class of business represents, at the present time, a comparatively small amount, and we are not ready for an association of this kind for the reason that the revenue represented is not sufficient to warrant the expense necessary to maintain and conduct such an association.

So far as Western New York is concerned, the toll line companies are having no difficulty in arriving at a division of revenue at a very small expense; in fact, at a cost of less than two per cent. of the gross business cleared. The real need is for a method of making a fair division in localities covered by short lines interchanging a large volume of business. If these different localities can be formed into associations, organized on similar plans and using similar methods, the results will be satisfactory throughout the State, and from these smaller associations we will gradually work into one joint traffic association in which the missionary work will have been accom-plished. No manager of a State traffic association could at the present time be familiar with the conditions in all localities covered by short connecting lines, and the serious complications which arise in establishing rates, regulation and routings come from just such localities.

A still better plan for bringing about a uniform toll service would be a concentration of short lines under one management, for instance, in certain counties in which a dozen or more separately controlled lines are interchanging business, an association or even a corporation could be formed from among the various connecting companies, which could lease all the connecting lines and operate them as one line, allotting to each company a division of the net revenue in proportion to the pole line mileage furnished.

"Unity of control" is a phrase which may not appeal particularly to a gathering of independent association men, but at the same time the more we can intelligently concentrate "control of operation" of our toll lines, the nearer we come to perfection in uniform and efficient toll service.

and Telephoning.

given, to eliminate the effect of either of them.

In the present case, we have the telephone current and an induced current due to the telegraph current, both exhibiting an alternate character, but each being of different frequency, the effect. of the induced current being the one to be annihilated.

In order to show how it is possible to attain this, the author considers a closed circuit, a certain section of which is divided into two branches of equal ohmic resistance, forming a differential coil wound on a weak iron core. Assuming that the two differential branches have different impedances, it will be understood that with a current of given frequency it is possible to regulate the two impedances, so as to have in the core a resultant flux equal to zero. If, therefore, two currents of frequencies, x1 and x,, be passed through the circuit, the latter being, for instance, regulated for

quency x, will give a flux different from zero. Now, if the weak iron core be the one of a telephone, the latter will show only the effects of the frequency x., and, generally speaking, all those of any other frequency either superior or inferior to x1. A similar circuit, capable of annihilating the effects on an external circuit of either of the currents evolving through it, has been termed separator by the in

ventors.

The separation, as stated above, is obtained for currents of alternate character; in the particular case of either of them being a telegraph current, the frequency of which may range between rather extensive limits, it will be necessary, in order to obtain the separation. that the latter should have a frequency included between the above limits; otherwise the corresponding telegraphic frequencies would be, as well, eliminated.

It may finally be understood, as clearly shown by an analytical discussion of the problem, that the separator will eliminate not only the effects of a current of one single frequency, but those of a certain number of frequencies as well, all of which are very near the theoretical frequency, producing a perfect compensation. For frequencies scarcely different from this theoretical frequency the effects on the membrane will, in fact, be very small, on account of the inertia of the latter.

Ordinary telegraphic currents will produce induced currents with frequencies going as far as about 200 periods. Now, as the Brunè-Turchi separator is capable of annihilating the effects of currents having frequencies as high as 200 periods, if in any circuit induced telephonic currents with frequencies of the order above stated and telegraphic currents (the frequencies of which, as is known, are much superior to 200 periods) are present at the same time, the separator will annihilate the effects of the former, those of the latter remaining active; in other words, the telegraphic

transmission will in no way disurb the telephonic transmission.

The scheme of the arrangement adopted by the inventors is sketched in Fig. 1. One of the three windings forming the coil R is inserted in series with the telegraph line, one of the other two windings being used for the insertion of the microphone M, the other forming part of the separator circuit. This circuit, as stated above, is divided into two branches, including capacities C' and C" and an inductance, and terminating in two differential windings wound on an iron core F, forming at the same time the core of a third winding used for the telephone T.

through the focal line of an especially constructed cylindric lens, concentrating the light from a "speaking" arc lamp on to the film. The latter, after the record. has been made, is developed and fixed, when a strip of constant breadth including alternate dark and bright vertical lines is noted on the developed film, corresponding closely to any alterations in the candle power of the source of light at the sending station and accordingly to the transmitted sound waves.

In order to reproduce the language, the "photophonogram" thus obtained, or else a positive obtained from the latter, is drawn along at the same speed as when the record was made before a similar apparatus, while the light rays from an ordinary projection lamp are allowed to strike it. The different shades of the film will result in the light rays from the above lamp being absorbed to various degrees, thus producing a variable illumination of a selenium cell arranged behind the film. The latter, accordingly, will be exposed to an illumination of variable strength analogous to an illumination from the light source at the sending station, these luminous variations being converted again in alterations of the electric resistance of the selenium, thus giving rise to current oscillations, that act on the telephones inserted and thus reproduce the telephonogram. In the case of the distance between the sending station and the photographophone being small, the apparatus simply constitutes a novel photographic phonograph, the lamp used as speaking arc serving in the reproduction as projection lamp for illuminating the film. In the case, however, of the distance being greater, the apparatus at the same time represents the solution of the problem of simultaneous transmission and recording of the sound waves of the human voice. A special advantage is the fact that both the positive and negative may be used and that from any original negative any desired number of equivalent copies, being positives, may be produced.

The Telecryptograph.

An Italian electrician, Signor E. Malcotti, is engaged in the construction of a telegraphic apparatus meeting the following requirements: First, the appar

atus should be susceptible of being used on any existing telephone lines without any previous alteration of the latter; second, the secret of any communication should be warranted, and third, the construction should be simple and the price of the instrument low.

The apparatus, the first type of which has a short time ago been brought out, shows some analogies with the telephonetelegraph apparatus described in these columns, being also a printing telegraph, but the most important distinguishing feature is the fact that there is no necessity of installing any special exchanges and special lines, but that any existing telephone plant is ready for the "telecryptograph" service. The apparatus is worked by currents analogous in every respect to telephone currents and therefore interfering in no way with the ordinary telephone service. On the other hand, the secret of the dispatch is warranted by a device allowing of any two apparatus being tuned for a figure established beforehand, so as to keep the telegram secret throughout the line as well as at the house of the receiver, the messages arriving as ciphered telegrams. The receiving apparatus may be caused to decipher automatically the dispatch. either after reception or during the :same. The number of ciphers the apparatus is susceptible of is upwards of 6 milliards, thus being practically infinite.

On Wireless Telephony by Means of Hertzian Waves.

In a recent issue of La Energia Eléctrica, Madrid (May 25, 1904), Mr. G. J. de Guillén Garcia records some interesting experiments made by him in conjunction with his son. In connection with some wireless telegraph researches, the son of the author happened to note that in the telephone of the Tommasi coherer located at the receiving station, there was a sound difference according to the air gap in the interrupter of the Rhumkorff apparatus. This suggested the idea that a similar apparatus would be susceptible of transmitting the human voice to a distance without the agency of the wire, and after this experiment had to be put off for some time because of the lack of a suitable outfit, the author was eventually enabled through the

courtesy of Prof. Marcel of the Barcelona Seminary to carry out his idea.

The experimental arrangement is a rather simple one; at the transmitting station there is a Rhumkorff apparatus 3 cm. in spark length, as well as the necessary oscillator, a small antenna and a grounded conductor. Between the transformer (i. e. the Rhumkorff coil) and a small battery of Grenet cells, there is a special microphone acting both as manipulator and as interruptor. The automatic interruptor of the induction coil is stopped while the condenser is used for enforcing the oscillator spark.

At the receiving station, there is a Tommasi coherer, connected to the receiving antenna and the grounded conductor. In a telephone receiver, the noise produced by the Hertzian waves on traversing the coherer is noted.

On approaching the mouth to the microphone and singing or speaking, every sound vibration will be attended by an interruption in the passage of the electric current through the primary circuit of the transformer, the number of sparks in the oscillator thus being varied. The underlying principle shows therefore some analogy with the mechanism of an ordinary telephone.

Any results so far obtained in the reproduction of singing are said to be quite satisfactory, whereas the rendering of language leaves much to be desired. The feeble point seems to be the difficulty of designing a microphone of sufficient intensity Mr. Garcia, it is true, has remedied the imperfections of his apparatus to a certain extent, by using a condenser and augmenting the potential difference; this, however, could not be driven too far lest electric arcs be formed.

A Novel Microphone.

A novel kind of microphone was recently presented by the inventor, M. Tariel, to the French Physical Society. The novel feature of the instrument is the special way of preparing the carbon grains and other similar bodies. After taking carbon plates only 0.15 to 0.2 m. in thickness of a perfectly plain and polished surface and breaking them by hand into small pieces, the fragments are passed through a sieve, the meshes of