730 



SCIENCE 



[N. S. Vol. XXXVII. No. 958 



In recent tests between the Arlington station 

 and the scout cruiser Salem on its voyage to 

 Gibraltar and return, messages were received from 

 Arlington in the day time on the Salem up to a 

 distance of 2,100 nautical miles, and at night as 

 far as Gibraltar. 



A comparison was also made of the action of 

 two types of sending sets, one being the regular 

 spark sending set and the other set in which the 

 waves are produced from an electric arc. It has 

 been claimed that the continuous waves emitted 

 by the arc are less absorbed than the broken-up 

 trains of waves produced by the spark. Up to 

 1,000 miles no difference in the absorption was 

 observed, but at 2,000 miles the observations indi- 

 cated that the received are energy was relatively 

 four times greater than that of the spark. 



Besonance in Badiotelegraphio Receiving Stations: 

 George W. Pierce, A.M., Ph.D. Introduced by 

 Professor Arthur W. Goodspeed. 



A New Form of Resonance Circuits: Michael I. 

 PupiN, Ph.D., Sc.D. 



The International Radiotelegraphic Conference of 

 London and its Work: Arthur Gordon Web- 

 ster, Ph.D., LL.D. 



The great development of wireless telegraphy 

 and the embarrassment arising from interference 

 in communication and the refusal of different 

 companies to transmit messages at sea led to the 

 necessity of international control, and brought 

 about the Conference of Berlin in 1906. It was 

 then decided that these conferences should be 

 periodic, and the second one was held in London 

 in June and July, 1912. The United States sent 

 a delegation of twelve members, representing 

 various departments, including the army, navy 

 and commerce and labor. The working of the 

 conference was described, and the strong personnel 

 of the representatives of the more than forty 

 countries represented. All governments except 

 that of the United States, owning the telegraphs, 

 are able to exercise absolute control, and were 

 represented by high officials of their post-office 

 and telegraph administrations, as well as by mili- 

 tary officers. 



The work of the conference was concerned 

 mainly with the questions of prevention of inter- 

 ference between different stations, of increasing 

 the safety of vessels and of the prevention of 

 abuses in improper competition, the latter being a 

 matter in which this country was not interested. 

 The question of interference occupied the major 



part of the time of the conference. Two standard 

 wave-lengths were adopted, which were made 

 obligatory, so that there could be no excuse for 

 not hearing messages. The amount of power to 

 be used was limited, so that it should not be in 

 the power of one station to drown out others. 

 On account of difficulties in crowded waters like 

 the English channel, surrounded by several nations, 

 strict rules of precedence were established and 

 the multiplication of useless calls was restricted. 

 Attempts to overreach one country by powerful 

 stations belonging to another caused considerable 

 feeling and were regulated. 



In the interest of security, all stations are to 

 be licensed by their governments. Operators must 

 also be licensed, and shall be of two classes, ac- 

 cording to proficiency. Operators of the second 

 class are to be permitted only on small ships, and 

 as substitutes on those having one operator of the 

 first class. The wireless stations are put under 

 the authority of the officer in command of the 

 ship. On passenger ships there must be a special 

 emergency plant capable of operation indepen- 

 dently of the ship 's power, and strong enough to 

 reach eighty miles. Such stations must listen for 

 distress calls for ten minutes of each hour. High- 

 power shore stations must periodically cease trans- 

 mitting, in order not to interfere with distress 

 calls. Distress calls are given absolute preference. 

 The transmission of meteorological news is facili- 

 tated by giving it priority, when sent to certain 

 designated designations. 



The author expressed the opinion that in spite 

 of all that had been done, before the next con- 

 ference, to be held in Washington in 1917, wireless 

 traffic would have so increased that much more 

 stringent regulations, as well as improved methods 

 of tuning, would be necessary. 



A general discussion followed, led by Professor 

 Elihu Thomson. 



At the annual dinner on Saturday evening, at 

 the Bellevue-Stratford, over one hundred members 

 and guests were present, the toasts being re- 

 sponded to as follows : 



' ' The Memory of Pranklin, ' ' by His Excellency 

 the French Ambassador. 



' ' Our Guests, ' ' by Professor Arthur Schuster. 



"Our Institutions of Learning," by Professor 

 A. G. Webster. 



' ' The American Philosophical Society, ' ' by Mr. 

 Hampton L. Carson. 



Arthur Willis Goodspeed 



Philadelphia, 

 April 23, 1913 



