which signals emanate may be determined, whether the radiation source be a horizontal antenna or a vertical antenna. It will be understood of course that the antennæ A 105and A′ may be rotated about a vertical axis or, preferably, as shown in Fig. 6, a number of horizontally extending antennæ A1, A2, A3, etc., may be used and a switch Q cooperating with the contacts U may be 110employed to connect any desired antenna with the oscillation detector circuit. While the antenna need not be horizontal, the directive effect becomes less noticeable as they approach the vertical.
115The receiving antennæ A′ may be as long as desired for instance from 200 feet to one quarter of a mile in length, and they may be supported by relatively short poles H, H, as indicated in Fig. 5, so that the elevation 120of the antenna may be small as compared to their length. No supporting poles need be used when the ground is a poor conductor, and good results have been obtained by merely laying the antenna along the 125ground as shown in Fig. 4.
Fig. 7, W represents a railway track and X the telegraph wires which usually are strung on poles beside the track. The antennæ A and A′ are shown as placed near 130the telegraph wire and as grounded on the track. I have discovered that all longitudinal cross-country conductors, such as railway tracks and masses of telegraph or telephone wires act as wave-chutes and lead 135off waves in the direction in which they extend, thus draining the ether of the wave energy in their immediate neighborhood. Thus if a transmitting system, having either a vertical or horizontal antenna, is operated 140in the immediate vicinity of a railway track and is grounded to the rails, or in the immediate vicinity of a line wire system, a maximum field of force will be created in the direction of said track or line wire system. 145Preferably, as shown in Fig. 7, horizontal transmitting and receiving antenna should be employed, the lower ends thereof being grounded on the track and the horizontal portions paralleling the track and line 150wires in which case an enormous field of force will be concentrated between the two parallel conducting systems. By this means the distances by which signals may be transmitted by electromagnetic waves overland 155may be greatly increased. The receiving apparatus will respond to the electrical oscillations created by said waves in the antenna A′, but as ascertained by experiment, will not respond to any induction effects which 160may be created in said antenna A′ by telegraphic or telephonic currents traversing the line wires X.
In Figs. 8, 9 and 10 the transmitting station may be placed at a relatively short distance from its home receiving station and165 may be situated approximately in the perpendicular bisector of the horizontally extending portion of the antenna of said home receiving station. Each receiving antenna A′, A′1, preferably is directed toward its 170corresponding district transmitting station, as indicated by dotted lines. By so arranging the antennæ A′, A′{{sub}3}}, by the radiation from the antennæ V′1, V′, respectively,175 so that duplex working is rendered possible. Preferably the receiving operator is located at the transmitting station and the current variations produced in the circuit of the oscillation detector may be 180conveyed to the operator’s head telephone by lead covered cable which may either be buried in the earth or carried by poles. If said cable is not buried it must be well earthed at both ends and at intermediate185 points, as shown in Fig. 9 in which J, J′, represent metal covered cables connecting the local circuits at R, R′, to the station houses T, T′.
Fig. 10 shows another way in which the190 signals received at R, R′ may be conveyed to receiving operators located at T T′. In this case the horizontal antenna is connected by the wire Y with one primary N′ and a dummy wire Z is connected with the other195 primary N, so that the strong signals transmitted from the home transmitting stations will be neutralized upon the secondary O and no effect will be produced upon the oscillation detector D. Weak signals from the200 district transmitting stations will develop currents in the secondary O which will cause the detector to respond.
I claim:
1. In a system of wireless telegraphy a205 substantially horizontal receiving antenna, divided into two parts, each connected to a detector between them, in correspondence with a substantially horizontal transmitting antenna in the same vertical plane.210
2. In a system of wireless telegraphy a substantially horizontal receiving antenna, divided into two parts, each connected to a detector between them, in correspondence with a substantially horizontal transmitting215 antenna in the same vertical plane, and having its generator end nearer to the receiver than its tail end.
3. In a system of wireless telegraphy, a substantially horizontal transmitting 220antenna and a receiving antenna, said transmitting antenna being substantially in the vertical plane passing through said receiving antenna.
4. In a system of wireless telegraphy, a225 substantially horizontal reveiving antenna and a transmitting antenna, said receiving antenna being substatially in the vertical
