US884109A

US884109A - Space telegraphy.

Info

Publication number: US884109A
Application number: US32909606A
Authority: US
Inventors: John Stone Stone
Original assignee: WILLIAM W SWAN
Current assignee: WILLIAM W SWAN
Priority date: 1906-08-03
Filing date: 1906-08-03
Publication date: 1908-04-07
Anticipated expiration: 1925-04-07

Description

I No. 884,109.

J. -S. STONE. SPACE TELEGRAPHY.

APPLICATION FILED AUG. 3, 1906.

PATENTED APR. 7, 1908.

5 SHBETS -SHEBT 1.

-@JZTENTPD APR. 7, 1908.

J. S. STONE. SPACE TBLEGRAPHY; APPLICATION FILED AUG. a, 1908.

'a SHEETS-SHEET 2.

J. S. STONE.

SPACE TELEGRAPHY. APPLICATION FILED AUG. 3, 1906.

PATENTED APR. 7, 1908'.

5 SHBETSSHBET 3.

No. 884,109. PATENTED APR. 7, 1908.

.LQS. STONE.

SPACE TELEGRAPHY; APPLI ATION FILED we. a, 1906.

a SHEETS-SHEET 4:.

PATENTED APR. 7, 1908.

J. S. STONE. SPACE TBLBGRAPHY. APPLIOATION FILED AUG. 3, 190's.

6 SHEETS-SHEET 6.

igJEL JLJ k Mn 51 1 M E v M N11 T ww UNlTED STATES PATENT curios.

9 JOHN STONE STONE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOB. TO WILLIAM W. SWAN, TRUSTEE, OF BROOKLINE, MASSACHUSETTS.

SPA CE TE LE GRAPHY,

and useful Improvement in Space Telegraphy,

of which the ollowing is a specification.

This invention relates to the art of trans-. mitting intelligence from one station to another without the use of wires to guide the waves -to their destination; and it relates more particularly to systems for receiving signals transmitted by such waves.

The object of the resent invention is to so adjust the elevateiv conduct-0r system of a wireless telegra'h receiving system relative to an associateituned or resonant receiving circuit or circuits that, first, a persistent train of electromagnetic waves of a predetermined. frequency impinging upon the elevat-ed conductor shall cause the associated circuit or circuits to respondenergetically; that, second, a ersistent train of electromagnetic waves of requency other thanrsaid predetermined frequency impinging upon the elevated conductor shall cause the associated tuned or resonant circuit or circuits to re-.

s 0nd but feebly or. not at allfand that, t iird, abrupt or impulsive electric forces acting upon t 1e elevated conductor shall like- -wise produce but feeble response c no respouse at all in the associated tune: or res onant circuit or circuits.

The first and secondobjects of this invention may be attained by givin the elevat vd conductor system a pronounced fundamental rate of vibration equal in frequency to that to Which the tuned or resonant receiving circuit or circuits is attuned. The first and second objects of this invention may therefore be attained by placing a suitable inductance or capacity in theelevated conduc} .tor near its connection to earth, if itbe an eanthed elevated conductor, or at thecenter of the receiving conductor, if it be an un{ hart-lied conductor, asfthereby the receiving conductor system will be given a pronounced and predeterminedrateof vibratibn much as a; stretched string may be given a predetermined and more pronounced rate of vibration byv the addition of a suitable load at its .,,eonter. ,If 'herefore,theloadin inductance '01 capacity added he made such as t-o give the eievated conductor system a'pronounced rate .of vibration equalto the frequency towhich Specification of Letters Patent.

Application filed August 3, 1906. Serial No. 329,096.

Patented April 7, 1908.

the associated tuned or resonant receiving circuit or circuits is attuned, the first and second objects of the invention will be realized. This simple expedient, however, is not sufficient to accomplish the third object of the present invention, and for this purpose I may give the elevated conductor system a pronounced natural rate of vibration difiere ent from thatto which the associated tuned or resonant circuit or circuits is attuned while making the elevated conductor system highly res onsive to persistent trains of waves of t e frequency to which the.associated tuned or resonant receiving circuit or circuits is attuned. For the pur )ose of accornplisl'iin the third object of t e resent invention fmay also provide means aving i or such natural vibrations as may by abrupt or impulsive electrical forces be created in the elevated conductor, practically zero reactance, or, at least, an impedance low as com ared to the impedance of the means by whic i the tuned or resonant receiving ,circuit or circuits is associated with the elevated conductor system, whereby such naturalvibrations may be conducted to earth around such associating means and hence prevented from passing through said means and thereby producing even a feeble response in the aforesaid tuned or resonant receiving circuit or.

vated conductor system a pronounced natural rate of vibration different from that of the waves the energy of which is to hereceived, and, consequently, diiferent from that to whic, the associated tuned or resonant receiv'ing circuitor. GlIClLilS is attuned; by making the elevated conductor system highly responsive to persistent trains of waves havin the frequency of those the energy of which is to be received and, consequently, the frequency to which the associated tuned or resonant rece1vin circuit oo or'circuits is attuned; and iinally. y con veying such'natural. oscillations as may be developed in the elevated conductor by ex 'traneous electrical impulses of frequency different from that to which the tuned or resonant receiving circuit or circuits is attuned, or such as may he developed therein by abrupt or impulsiye electrical forces, to earth around the means wherebysaid tuned or resonant receiving circuit or circuits is associated witi'i the elevated conductor s us.

One of the several embodiments of my inwntion whereby the above mentioned objects have been realized in practice .consists of an elevated conductor system comprising circuit including a serially connected coil and condenser, an elevated conductor and an earth connector; the elevated conductor and earth connector being connected in iarallel with respect to said circuit and each, when isolated, for the same frequehcy, that is to say, the furniamental period of the elevated conductor, when isolated, being equal to the period of the earth connector, when isolated; and said circuit having, for persistent elec trical.osciliations of the frequency of the waves the energy of which is to be received, a reactai'icc equal in value and opposite in 1 to the resultant rcactance of the elevated conductor and its earth connector. The results are. that the earth connector determines, the most pronounced natural rate of vibration of the elevated conductor system because, for either natural or forced -trical osr.:.illations having such rate of vihration, the reaction of the aforesaid circuit which includes the serially connected coil and condenser upon the rest of the elevated conductor system is zero, said circuit being shunted by the earth mnnector which for such OLiKlillZtllUIlS has zero reactance and practically Zero impedance; that the aforesaid circuit which includes the serially connected coil and condenser, by balancing the resultant reactance of the rest of the elevated conductor system for persisteiit electrical oscillations having the frequency of the waves the energy of which is to be received, renders said system highly responsive to persistent oscillations of such frequency; and, that the earth connector, having zero reactenice and practically zero impedance for electrical oscillations having the frequency of the most pronounced natural rate of vibratioi'i of the elevated conductor system, conducts such natural oscillations as may be (,lcveloped in the system to earth around the aforesaid circuit with which the resonant receiving circuit or oscillation detector may be associated.

The present. invention is a dcvelonncut ofthose described in my l 5. Letters fateut Nos. 767,994, dated Aug. lo, 1!;04, and 802,417, 402,421, sea-'12.". and sneeze.

dated Oct. 24, H105, to which reference may he had for a more complete c. '1 lanation of certain ofthe gcneral prim-ipfcs involved i. tlntprcscnt application than need he set l'orth herein, and it is especially a develop ment and lmnlilicatioi'i of the invention described in my application Serial No. 329,0h4, liled simultaneously herewith, in which i. have fully explained certain of the having zero reactamte scenes particular principles involved in the present application. Y

My invention may best be understood by having reference to the drawings which accompany and form a part of'this secification and which diagrammatically ilustratc organizations of circuits and apparatus whcrel'iy the hereinbefore stated objects may conveniently be realized in practice. I

In the drawings, Figure 1 is a diagram representing a space telegraph receiving system which embodies my invention in its simplest form. Fig. 2 is a diagram representing another and preferred form of my invention. Figs. 3 to 12 inclusive show a set of curves drawn to rectangular coordinates in which the ordinates represent reactances or current amplitudes and the abs isszc represent frequency, which illustrate the proportionment of the various elect. .-n1agnetic constants of the several elements of the systems shown in Figs. 1 and 2, and which graphically set forth the mode of operation of the invention.

1n the figures, V is an elevated conductor per se.

E is an earth connection.

(1 C, C, are condensers.

L L, are inductance coils.

I, and I, are the primary and secondary coils of the transformer M, said coils being preferably so spatially related that the mutual energy between the primary and secondary circuits is small as compared with the product of the self energies of said circuits.

W 's an oscillationdetector of any suitable construction and is herein shown as consisting of a Wollaston anode immersed in an electrolyte.

T is a signal-indicating device which may he a telephone receiver.

B is a batter and It is an adjustable resistance, said attery and resistance constitutin a potentiometer.

The three essential elements of my invention are the elevated conductor V0, the earth connector 0 L C, shown herein as earthed at E, which is the same point at which the circuit 0 1, C is earthed, although it will be understood that the circuits 0 L C and o i, (I, may have separate earth connections, andthe circuit which includes the serially connected coil and condenser I, and Q.

My invention resides in the arrangement of the aforesaid eiementsand in the proportionmcnt of their electromagnetic constants wl'ierehy the foregoing objects may he.

has zero reactance, so that for natural oscillations of a frequency equal to the most pronounced natural rate of vibration of the cuit C 1 is attuned, a 'reactance equal and,

opposite to the resultant reactancc of the elevated conductor V0 and earth connector 0 L C E, which are connected in parallel with respect to the system 0 1 -0 E.

The system, 0 I 0 E together with the elevated conductor Yoand earth connector 0 L C E, which are connected in parallel with respect to the system 0 I C E, constitutes the eleyated conductor system. For persistent ,electrical oscillations of the frequency/ 0 which the resonant receiving circuit Q; 2 is attuned sald elevated conductor system has zero reactance, the resultant reactance of the two components V0 and -0 L C E of said elevated conductor system being balanced by the reactance of the circuit which includes the, inductance I and the capacity 0,. Under these circumstances it will be seen, es ecially b reference to the curves shown in igs. 4 am 9, that the earth connector 0 L C E and the circuit which includes the coil I and condenser C constitute a parallel branch circuit having for persistent electrical oscillations of the frequency of the waves the energy of which is to be received, a reactance equal and opposite to the reactance of the rest of the elevated conductor system, so that said system is highly responsive to electrical oscillations of said frequency; and that one branch of said parallel branch circuit", namely, the branch 0L C E, E in this case being common to both branches, has such capacity and inductance that the reactance of said branch is zero for the frequency for which the reactance of the elevated conductor is zero, so that the elevated conductor system thereby is given-a pronounced natural rate of vibration different from that of the waves the energy of which is to be received.

of said earth connector is the same in sign and is approximately the same in value as the reactance of said elevated conductor; and the elevated conductor and earth connector, when'isolated, each has zero reactance for oscillations of' the lowest frequency natural to the elevated conductor. However the selectance function of the earth connector for a given frequency may be made equal to that of the elevated conductor for such frequency by any suitable means.

The circuit C, I is a resonant receiving circuit attuned to the frequency of the waves the energy of which is to be received and associated in the present instance with the inductance L which is included in the circuit The oscillation detector W and the local circuit including the same may be associated with said resonant receiving circuit in any suitable manner, and in the present instance are shown as connected across the terminals of the condenser C In the manner more fully set forth by me in my Letters Patent N 0. 767,994 hereinbefore referred to, the parallel branch circuit I C, gives the entire elevated conductor system shown in said Letters Patent natural rates of vibration different from that of the waves the energy of which is to be received while for a persistent simple harmonic forces having the frequency of said waves, the reactance of the parallel branch circuit balance the reaction of the rest of the elevated conductor system and thereby makes said system highly responsive to persistent forces of said frequency. in the. systems described in said Letters Patent, thcnatural oscillations developed in the elevated conductor system are of frequencies ill adapted to cause a response of the associated resonant receiving circuit'by passing to earth through the parallel branch circuit with which said resonant circuit is associated, on account of the high impedance offered by said resonant circuit to naur'al oscillations of said frequencies. Such natural oscillations, however, pass to earth through the parallel branch circuit and if they are of sufliciently high intensity they may produce a noticeable response of the associated resonant receiving circuit unless the mutual inductance between said parallel branch circuit and said associated resonant circuit be made excessively small.

The particular improvementeffected by the present invention over the state of the art as shown by my hereinbefore inentioned Letters Patent consists in obviating even a tendency for said natural oscillations to pass through the circuit with which the resonant receiving circuit is associated. To this end I may employ means whereby the elevated conductor system is given natural rates of vibration different from that of the iLSSOlf/lflm' day seams natural oscillations as may by extraneous forces be created in the elevated conductor from passing through the circuit which ineludes the serially connected coil and condenser l, and C said latter means comprising preferably the earth connector 0 L C E, which, for natural oscillations having a frequency equal to the most pronounced natsaid system may be made highly responsive to persistentelectrical forces of the frequency to which said resonant receiving circuitis attuned and that for oscillations having a frequency which is equal to the most pronounced natural rate of vibration'of said system, the reactance of the elevated conductor V0 and the earth connector 0 L C E, as well as the reactance of the system no L C E, is

zero.

Having set forth in general the fundamental Y inciples of my invention I shall now deseri e specifically those embodiments thereof which are illustrated in the drawings accompanying this application, although it will be understood that I do not limit myself to such particular embodiments of the present invention, inasmuch as many modifications may be made therein by those skilled in the art without departing from the principle or spir t of my invention.

In order that the particular embodiments of my invention which I have selected for diagrammatic illustration for the purpose of more fully disclosing the same may be de scribed with sutiicient particularity to enable those skilled in the art to make and use the same, it ,will be necessary to refer to the curves shown in Figs. 3 to 12 inclusive.

Figs. 3 and 4 show the variation with frequency for persistent electrical forces of the reactance of the several components of the system illustrated in Fig. 1; Figs. 8 and 9 show thevariation with frequency for persistent electrical forces ol the reactance ofv the several. components of the system 1l lus-" trated in Fig. 2; Figs. 5, 6 and 7 show the variation with frequency for persistent electrieallorcesot the current amplitudes of the several parts of the system illustrated in Fig. I

1; and Figs. ll), 11 andl'Z show the variation with freq ncy for persistent electrical forces of the current amplitudes inthe several parts of the system illustrated inl ig.- 2.

A practically infinite number of relations may exist between the ire uencies natural to the circuits 0 1, C, and 0 L although for the purpose of conveniently representing in Figs. 3, 4, 5 and 9 the various relations shown therein, I ha ve chosen the frequency natural.

to the circuit I, C, as equal to one-half of the frequencv natural to the circuit L C. In all cases the frequency natural to the earth con: hector l; C is equal to the fundamental ire- ,quency of the elevated conductor V0, whether 01 not the coil L, be employed.

In the following discussion of the curves shown in Figs. 3, 4, 3 and 9 it is to be understood that while said curves give the values of reactances whereby the several com onent parts of the system may be designs I do not limit myself to systems, the component parts of which necessarily have the reactances shown in said curves inasmuch as an infinite number of systems mav be designed in accordance with the princip e of the pres .ent invention, the reactances of whose eomponent parts would be vastly different from those shown insaid curves. So far from limiti myself to s stems designed according to t e aforesaid curves, 1 consider said. curves merely as illustrative of two special cases of the present generic invention, that is to Figs. 3 and 4 are illustrative of one specific case shown in dis am in Fig. 1, in which an unloaded vertica -isemployed and. Z";

and 9 are illustrative of one specific case shown in diagram in Fig; 2 in which the loading inductance L,is serially connected with the elevated conductor V 0.

The reactance of the elevated conductor system at the point 0 may most conveniently be found b adding the conductances of the circuit 1, (l; and the earth connector, and then adding the reactance of the elevated conductor at the point 0 to the reciprocal of such joint conductance'i. e.,the joint reactance. For convenience, the term core ductance is used herein as meaningthe reciprocal of reactance.

Curve (1) in Fig. 3 shows the react-ancef'requency variation of the dircuit I, C, and curve (2) shows the'cot:'luctance-irequency variation thereof. 7

Curve (3) shows the reactance-frequency variation of the earth connector and curve (4) shows the conductancerfrequencyvariation thereof.

Curve (5), being the algebraic sunrofcurves (2;- and (4.), represents the variation with frequency of the joint -(inductance the two circuits 1, C, and L (I, or the total conductance of the parallel branch circuit 0 I, C, L C. m, at which curve (5) crosses the .axis of abscissa therefore represents the irequency natural to said parallel branch -:r-

cuit. when 'isolateth'and for persistent electrieal forces of said frequency the reactance of said parallel branch circuit as measured between its points of connection with the one as explained in connection with Figs. 5. 6 and 5 cuits G, and LC or the total reactance of the parallel branch circuit 0 I, C, L C, and for persistent electrical .forces of frequency a, the ordinates of said curve are im'inite as shown ii -Fig. 4 in which curve (6) is asymp- 1o .totic to'the ordinate drawn from the oint 'n,

onthe axis of abscissa Thus it w be seen that the parallel branch circuit 0 I, C, L C

presents thesegcharacteristics, that for persistent electrical oscillations of frequency it,

.15 its reacta'nce on the driving oint is praQtically infinite, while for nature oscillations of ire uencies n and n, being thosenatural-to, its ranches I, O and L C respectively, its reactance is zero, as hereinafter more fully 7.

Curve (7) represents the variation wigh frequency of the reactance of the elevat d conductor V 0, in Fig. l, as measured at its electrical center 0.

(Jurve (8), which, is the algebraic sum of curves (6) and (7 represents the variation with frequency of the total reactance of the elevated conductorv system as measured at the point 0. Curve (8) crosses the axis .of

abscissae at two points, namely, n and a.

For electrical oscillations of frequencies a and n" therefore the reactance of the elevated conductor system is zero.

n represents the frequency of the waves SS the energy of which is to b e received and to which the resonant receiving circuit is at-.

tuned, and for ersistent' electrical forces of this frequency t e reactance of the circuit including the serially connected'ccil and con-. 40 denser I and'C is equal in value and o posite in sign to the resultant reactance o the elevated conductor V0 and its earth connec'tor 0 L C E which are connected in parallel with respect to said circuit.

of frequency n, the reactance of the arallel branch circuit 0 1 C, L C is equal am opposite to the reactance of the rest of the elevated conductor system, as clearly shown in Figs. 4 and 9, in which the ordinates of curves (6) and (7), or (6) and (7'),at abscissae n are, pair by pair, equal in value and opposite in sign.

n represents the fundamental frequency natural to the elevated conductor V0, when nounced and gravest natural rate of vibration of'the elevated conductor V0 and earth connector 0 L C E connected in series and isolated and finally n represents the most pronounced natural rate of vibration of the elec5 vated conductor system considered as a Stated in v 45 another way, for pcrsistent electrical forces whole i. 6., V0 and o L C E connected in series with each other and in parallel with respect to I C,,because for oscillations, either natural or forced, of frequency 47/ the circuit 1, C, does not react upon the system V 0 L C E inasmuch. as said circuit 1, C is shunted by the earth connector 0 L C E which for oscillations of said frequency has zero reactance and practically zero impedance. Accordingly electrical oscillations of frequency n wlnchare developed in the eleearth connector and have no tendency to resonant receiving circuit is associated with the elevated conductor system, said means being the circuitl (1,. The natural oscillations which are developed in the-elevated conductor by abru t or impulsive electrical -forces are chiefly oi frequency 72/, that is to sa the most pronounced natural rate of vi ration of the elevated conductor system is determined by the earth connector and is not aiiected by the circuit I, 0,. Curve (9) shows the variations with freuency of the resistance equivalent of radiatron of the elevated conductor V0 in Fig. l, and the ordinate of curve (9) for frequency n is 40, irrespective of its geometric or electromagnetic constants. This value accordingly fixes the scale of ordinates for the other scissee of said curve areex ressed as arbitrary numbers'l, 2, 3 etc., an these numbersmay be multiplied by the proper constants such as 7 .10 10, 2.10 etc, to suit the ordinary working conditions of wireless telegraph practice.

'lhe durve in Fig. 5 shows the variation with frequency for persistent electrical forces of the anipli' tude of the current developed in the elevatedlconductor V0 of Fig. 1 at a point slightly above the point 0 therein.

The curve in Fig. 6 shows the variation 1 with frequency for ersistent electrical forces of the amplitude o the current developed in the circuit I (3,. For frequency a, which is that of the waves the energy of which is to be received, there is a sharply defined current maximum in said circuit, while for frequency nthe' current in said circuit is zero because, as above pointed out, theearth connector which is connected in shunt to said circuit has zero reactance foroscillations of frequency n. g

The-curve in Fig. 7 shows the variation with frequency for ersistent electrical forces of the amplitude o the current developed in the earth connector. While a well defined and in fact relatively large current maximum occurs at frequency n, nevertheless said amlitude in the resent instance will be seen to lie about oneialf of that for which said frequency is developed in the circuit I, 0,, i owing to the fact that the reactance of the vated conductor pass to earth by way of the pass to earth through the means whereby the i curves shown in Figs. -3 and 4. The abthe curve shown in Fig. 5 is Zero for l'rej limit mysell to such means for associating quency n because, as above noted in com nection with Figs. 3 and 4, the reactant-c oi the arallel branch ci' hit 0 I ll (T is pmctica y infinite for persistent electrical l'orcc with respect to "the circuit. 11 .l, (1,. it will be seen that the sum of the currents in said elevated conductor and earth connector equal to the current in the circuit r I, (1

In Figs. 26 and 28 of my Letters Patent No. 767,994 above referred to, are shown curves somewhat similar in shape to the curve shown in Fig. 5 of the present case and representin the variation with frequency for persistent e cctrical forces of the current amplitudes in the elevated conductor. in the system disclosed in said Letters-Patent natural oscillations created in the elevated conductor system by extraneous electrical forces pass to earth through the parallel branch circuit L C as indicated at n in Fig. '34 of said patent. In the pres nt invention. how-- ever, the circuit 0 L C I; connected between the earth and the point of association of the circuit I G with the elevated conductor constitutes a path of practically zcro reactancc for any natural oscillations ol frequency n that may he created in the elevated conductor by such extraneous forces. because, for such natural oscillations so created. the reaction of the circuit I C upon. the system V 0 L CE is Zero, so that said oscillations have no tendency to pass'to earth by way of the circuit l C and therefore have no tendency to cause a response of the resonant re ceiving circuit which may be associated therewith. For such natural oscillations of 'said frequency so created in the elevated conductor by extraneous electrical forces the circuit I (I, has a reactant-e which in the present instance is very llhfll as compared to that of the circuit 0 l. (I la, as shown in Fig. 3 or, in other words, said circuit 0 l (T if, affords a path to earth around said circuit 1 C of practically zero impedance for such natural oscillations of said ir(- quei'icy. so that said than that of the circuitl (1,.

the circuit I C as shown in Fig. 3, so that there is but little tendency for persistent oscillations of frequency 7bi. c the frequency of the waves the energy of which is to he re ceivcd, to pass to earth by way of saidmirwit 0 L (J I).

As shown in Figs. 1 and 2 the oscillation detector W is associated with the elevated conductor by means of the circuit which includes the serially connected coil I and condenser (7 through thc intermediary of the res onant receiving circuit 1 but i do not said oscillation detector with said elevated conductor, inasmuch as other means will readily suggest themselves to those skilled in this art. it will be seen therefore that my invcntion comprises an elevated receiving conductor Yo. an oscillation detector W, mcans associating said oscillation detector with said elevated conductor. said means being shown in the prcscnt instance the circuit l t, and a circuit connected around the latter and being shown in the present instance as the fitl'tll connector 0 11 C E. it will be seen also that said circuit l C has, for persistent electrical oscillations of frequency n. a rcactance smaller than that of said earth connector while for such natural oscillations may be created in the elevated conductor said earth connector has a reactant-e smaller Furthermore it will he seen that my invention comprises a circuit. hercin shown as the circuit .l (1,, an elevated conductor Yo and an earth connec tor o L E, said elevated conductor and earth connector being connected in parallel with respect to said circuit and that, by virtue of thc pro 'iortionnient of the reactances ol' the various coniponents of the systcm a hcreinbeforc set forth, the system as a whole has zero reactance for oscillations of a. frequency equal to the Fundamental frequency of the elevated conductor o-viz t'nc ircquci'icy n, and has Zero reactance for one other l'requency, namely,- that of the waves of the energy of which is to he received; that currents of the frequency of the waves to be received, namely, 7:, pass chiefly through the circuit l C with which the oscilhition detector preferably is associated in any suitable manner; and that currents of ing coil L, is employed for stiftening the ele natural oscillations have practically no tendlectancc function.

ency to pass to earth by way of said circuit I C quency n the circuit 0 L li has reactant-e which is very high compared with that of For persistent clcct riczd lorccs of frvatcd conductor--i. 6., for elevating its se-' For the purpose of more readily comparing the reactance-frequcncy curves shown in Pigs. 8 and t) for the system illustrated in seams Figs. 10, 11 and 12 with those of Figs. 5, 6.

and 7, the fundamental n of the loaded ver tical of Fig. 2 is made equal to the funda{ mental of the unloaded vertical of Fig. 1.,

In other words, the fundamental of the elevated conductor pt! se of Fig. 2 is taken as higher than that of the elevated conductor per se of Fi 1. It will be understood of course that lar relation between the fundamentals of the elevated conductors per se of the two cases, and that the foregoingproportionnient has been made merely for the purpose of conveniently representing and comparing the two cases.

In Fig. 9 the fundamental of the elevated conductor per se is designated as n.

Curve (10) represents the variation with frequency of the reactance of the elevated conductor per cc of Fig. 2. l

. Curve (11) shows the reaetance-frequcncy variation of the inductance L of Fig. 2.

Curve (25'), being the resultant of curves (10) and (11), represents the reactance-freuency variation of the elevated conductor 0 cfFig. 2. Curve (6) shows the variation with frequeincy of the joint reactance of the two circuits which constitute the parallel branch circuit 0 I C L C. Curve (6) is, the reciprocal of curve (5), the latter representin t e joint conductance of the aforesaid pariillel branch circuit and being the algebraic sum of curves (2) and (4). Curves and (4) re resent the conductances of the circuits 0- 1 C, and o L C respectively, the reactances of which circuits are. shown by the curves (1) and (3). In the present instance the circuit I, C, of Fig. 2 is identical with the correspondingly lettered circuit of Fig. 1 as shown by the 'identity of curves (1) and (2) in Figs. 3 and 8.' The employment of th loading coil L, in the elevated conductor o Fig. 2 requires, other things being equal, that the earth connector of said figure be stifl'er than that of Fig. 1, and this is shown by the fact that:-

curve (3) is a steeper curve than curve (3). Curve (8), being the algebraic sum of curves (6) and (7), represents the variation with frequency of the total reactance of the elevated conductor system of Fig. 2 as meas ured at the point 0. Curve (8) crosses the axis of abscissae at two points, namely, a and 'n, in a manner similar to the corresponding curve shown as (8) in Fig. 4, with this differonce, however, thatin Fig. 9 the point n is higherthan in Fig. 4. The significance of theffr equencies represented by n and n in Fig.9, as well as those represented by n and n, in Fig. 9 is the same as that of the frequencies represented by the same reference characters. respectively, upon the axis of abscissae in Fig. 4 and discussed above in connection with said figure.

Curve (9) in Fig. 9 represents the variation with frequency of the resistance e 'uivalent of radiation of the elevated con uctor per se in Fig. 2, and the ordinate'of said; curve (9) is 40 for frequency n, which as above stated, represents the fundamental of the unloaded vertical V. fam not limited to any particu- The current-frequency variation curves shown in Figs. 10, 11 and 12 for the system illustrated in Fig. 2 present in general the same characteristics as those shown in Figs. 5, 6 and 7 for the system illustrated in Fig. 1. The most marked difference betweenthe two sets. of current-frequency variation curves is, that those shown in Figs. 10, 11 and 12 are in general steeperthan those shown in Figs. 5, 6 and 7, the reasons being that for frequencies a and n" the resistance equivalent of radiation for the system of Fig.

2 is less than that for the system of Fig. lat

the same frequencies respectively, and because the corn onent parts of the system are electrically sti er than those of Fig. 1. The

effect of employing the loading inductance L will be clear from an inspection of curve (8') which will be seen to be much steeper throughout its entire extent than the corresponding curve re resented as (8) in Fig. 4, thereby showing t rat the selectancc function of the elevated conductor system has been increased.

Although as above stated the frequency natural to the circuit 1, C, is herein shown'as less than the frequency n which is that natural to the elevated conductor V0 and its earth connectoro L C E, said frequency which is represented by it may have any value except the value n. It will readily be apparent that as the frequency n is elevated, the frequency n is increased, and that frequency it may be chosen as greater, than the frequency n, in which case the characteristic maxima for frequency a" which are shown in Figs. 5, 7, 10 and 12 will occur for frequencies lower than the fre quency n, or in other'words, the frequency of the waves to be received in such case will be greater than that of the elevated con-" l'lO ductor V0 and for said frequency, in such cases, the reactance'of the elevated conductor will be an inductance reactance. In the particular exam les herein given in curves (3), (4), (8) an (9), the reactance of the elevated conductor V0 for frequency 'n is a capacity reactance'and is balanced by the joint reactance of the two circuits which together form the parallel branch circuit 0 I, C, L C, said joint reactance being an inductance reactance. This particular proportionment, however, is not intended as a limitation, but is Hlclci incidental to the equal and opposite to the reactance of the particular example hosen for completely disclosing the prcscnt invention l in a space telegraph receiving system; an elevated comluctor system comprising an elevated conductor and a parallel branch circuit having for persistent electrical oscillations of the frequency of the waves the energy of which is to be received. a IOnttzllit't) i rest of the elevated conductor system, and each branch of said parallel branch circuit including a serially connected coil and con denser. v

6. In a space telegraph receiving system, an elevated conductor system comprising an elevated conductor and including a seriall connected inductancev and a parallel branc circuit having for persistentelectrical oscilequaland opposite to the reactant-c of thc 'lntions of the frequency ofthe waves the rest of the elevated conductor system, and one branch of said parallel branch circuit having such capacity and inductance that. said branch has zero reactant-e for the same frequency for which the rcactancc of the elevated conductor is xcro.

2. in a space telegraph receiving system, an elevated conductor system comprising'an 1 elevated conductor and a parallel branch: circuit having for persistent electrical bscillations ol' the frequency of the waves the energy of which is to be received. a reactance I equal and opposite to the rcactance of the l l l l l I rest of the elevated conductorsystem, and each branch of said parallel branch circuit including a serial v connected coil and condenser.

3. In a space telegraph receiving system, an elevated conductor system comprising an elevated conductor and a parallel branch: circuit having'lor persistent electrical oscillations oi the ircqucncv of the waves the energy of which is to he received, a reactance equal and opposite to the reactant-e of the rest of the clevatcd conductor system. and a resonant circuit associated with one branch of said parallel branch circuit. the other branch of said parallcl branch circuit having such capacity and inductancc as to form a path to earth having practically Zcro impedancefornaturalelectricaloscillalionscreated in the elevated c nduct n 4. in a .--pacc telegraph receiving system. an elevated conductor system comprising an elevated conductor and includin; a serially connected inductance, and a parallc branch circuit having for pcr istcnt electrical oscillations oi the frequency of the waves the energy of which is to be received. a rcactance equal and opposite to the rcactance ol' the rest of the elevated conductor sy tem. one branch of said parallel branch circuit having such capacity and inductance that said branch has zero rcactancc f r the same frcqucncy for which the rcactancc oi the ele- Yatcd conductor is Zero.

5. In a space telegraph receiving system, an elevated conductor system comprising an elevated conductor including a serially connected inductance. and a parallel branchcircuit having for persistent electrical oscillations of the frequency of the waves the I energy of which is to be received, areactance 1 energy of which is to be received, a reactance equal and opposite to the reactance of the rest. of the elevated conductor system, and a resonant circuit associated with one branch of said arallel branch cirucit, the other branch 0 said parallel branch circuit having such capacity and inductance as to form a path to earth having practically zero impedance for natural electrical oscillations created in the elevated conductor.

7. In a space telegraph receiving system, an elevated conductor system coin rising a circuitiincluding a seriallv connectet coil and =condenscr,"an elevated conductor and an earth connector; said elevated conductor and earth connector being connected in parallel with respect to said circuit and each, when isolated, having, zero reactance for the same definite frequency. 1

5% In a space tclcgrapl'i receiving svstern, an elevated conductor system comprising a circuit including a serially connected coil and condenser, an elevated conductor andan earth connector: said elevated conductor and earth connector being connected in parallel with res )et't to said circuit, and said circuit having, ior persistent electrical oscillations of the frequency of the waves the energy of which to be received, a reactant-e equal and opposite to the resultant reactant-e of said elevated conductor and its earth connector.

9. In a space telegraph receiving system, an elevated conductor system comprising a circuit including a seriallvconnected coil and condenser. an'elevatcd conductor and an earth connector: said elevated conductor and earth connector being connected in parallel with respect to said circuit and each, when isolated. having zero reactance for the same dclinitc frequency: and said'circuit having for persistent electrical oscillations of the frequency of the waves the energy of which is to be received. a rcactancc equal and o posite to the rcsultant reactance of said e evated conductor and its earth connector.

In testimony whereof, I have hereunto subscribed my name this 31st day of July 1906.

JOI lX $TON'E STONE.