TRANSACTIONS OF SECTION A. G39 



What led to this train of thoufrht was the fact that although the volume of 

 telegraphic current was immensely greater than that of a telephonic current, 

 whenever, through want of balance as a loop, disturbance was evident then tele- 

 phonic cross-talk was also manifest. In other words, a weak telephonic current 

 was apparently as powerful a disturber as a strong telegraphic one. 



The sensation created in 1897 by Mr. Marconi's application of Hertzian waves, 

 distracted attention froui the more practical and older method. Mr. Evershed 

 and Principal Oliver Lodge had, in the meantime, much advanced the system by 

 introducing admirable call systems. 



In 1899 I conducted some careful experiments on the Menai Straits which 

 determined tlie fact that the maximum effects with telephones are produced when 

 the parallel wires are terminated by ' earth " plates in the sea iLself. It became 

 quite evident that the ordinary inductive eflects are much enhanced by conductive 

 etl'ects through the water, and that in consequence shorter wires are practical. No 

 special apparatus seems necessary. The ordinary telephonic transmitters and re- 

 ceivers were used without induction coils. 



It became desirable to establish communication between the islands or rocks 

 known as the Skerries and the mainland of Anglesey, and it was determined to 

 do this by means of wireless telephony. The lighthouse at the Skerries was 

 wanted to be in communication with the coastguard station at Cemlyn. A wire 

 750 yards in length was erected along the Skerries, and on the mainland one of 

 three and a half miles from a point opposite the Skerries to Cemlyn. Each line 

 terminates by an earth plate into the sea. The average distance between the 

 parallel portions of the two wires is 2'8 miles. Telephonic communication is 

 readily maintained and the service is a good one. 



Further experiments with wireless telephony have recently been made by Mr. 

 Gavey between Rathlin Island, on the north coast of Ireland, and the mainland. 

 The east and west portions of the island of Rathlin are about eight miles from the 

 mainland, but a tongue of land projects southward to within a distance of four miles. 

 Communication was required between the lighthouse near the north-eastern corner of 

 the island and the mainland, and the question for solution was whether an over- 

 head line running the whole length of the island from east to west was necessary 

 to obtuio good communication, ol' whether a shorter line aci'osB the neck of the 

 southern peninsula would serve. The prelixninaiy experiments th<it h^.ve been 

 made prove conclusively that communication, both telegi'aphic and telephonic, has 

 been readily maintained by means of temporary wires established across the neclc 

 of the peninsula along the shorter line. Wireless telegraphy across the sea is 

 now a practical and commercial sjstem. 



No experiments have yet been made with ships, but it would appear simple to 

 speak by telephone between ship and ship or between ship and shore to consider- 

 able distances by means of a circuit formed of copper wire terminating at each 

 end of the ship in the sea, passing over the top-masts and using simple tele- 

 phones. 



5. On the Apparent Emission of Cathode Rays from an Electrode at Zero 

 Potential. By Charles E. S. Phillips. 



It has been noticed by many people who work with X-ray or other vacuum 

 bulbs that numerous bright green patches occasionally appear upon the inner 

 surface of the glass walls of a bulb while a discharge is passing, especially during 

 the process of exhaustion. 



These green flecks varv considerably from time to time in shape as well as in 

 position, and efforts have fceen made to connect their existence either with want 

 of uniformity in the composition of the glass or with irregularities in the surface 

 of the negative electrode. 



I have already, in another place,^ given some account of an experiment made 

 With the object of clearing up this uncertainty, and now beg to supplement that 



» Eldctrician, 43, 1898, p-p. 42S, 43G. 



