Transmitting Antenna in Wireless Telegraphy. 



antenna, and R 1? L 1? C 1? are the resistance, self-induction and 

 capacity per unit length of the wire. A solution* is 



R 



i — Ae 



2L " 2tt.tt 



cos -^tzm-^x 



where T = 4\/LC, I is length of wire, A is a constant and R, 

 L, C, relate to the whole length of the wire. The frequency 

 is 1/T and X = 4:1. From this solution it should follow that 

 the disturbance varies according to the simple harmonic law, 

 and that the free end of the wire is a potential loop, the lower 

 end a potential node. 



II. Experimental Arrangements and Results. 



In the present investigation all the wires explored were of 

 bare copper of diameter 7 mm and were stretched horizontally 

 on the tops of wooden poles about l'5 m high and l*6 m from 

 the wall of the room in which the experiments were made. 

 This room was a large hall, on the first flat, about 22 m long, 

 12 m wide and with a ceiling 13 m high. The manner of exam- 

 ining the wire at various points in its length was precisely 

 similar to that in the former research. The induction coil and 

 interrupter, the magnetometer and the method of taking read- 

 ings were identical with those used earlier and need not be 

 described again here. 



In most of the work the detector was the one used before, 

 but during the course of the experiments it was broken and 

 another, similar to it and indistinguishable from it in its beha- 

 vior, was constructed. 



The manner of applying the detector to the wire was slightly 

 different. Before, the detector was laid on the top of a car- 

 riage moving on ways along the wires, with the little wing, w, 

 fig. 1, in a little pocket by the wire; now, a small piece, c, of 



(a) 



(b) 



cylindrical hard-rubber rod, in which a groove was made down 

 to the axis, along a plane through the axis, was fastened to the 



* See Webster, Electricity and Magnetism, arts. 255, 256. 



