840 



WIRELESS TELEGRAPHY. 



for the economic development of the islands. Al- 

 though they have cost the Danish Government 

 $200,000 a year, the United States agreed to pay 

 $5,000,000 for them. 



WEST VIRGINIA. (See under UNITED 

 STATKS. i 



WIRELESS TELEGRAPHY. The contin- 

 ued development and improvement of wireless 

 communication (see Annual for 1898) seemed per- 

 haps to place us little nearer the commercial 

 utilization of this great discovery, until in the 

 latter part of 1901, and again in 1902, Guilielmo 

 Marconi, who since 1897 has been most usually 

 associated in the public mind with the subject, 

 demonstrated by successful experiment the possi- 

 bility of transatlantic telegraphy without wires. 



In December, 1901, Mr. Marconi sailed for New- 

 foundland in order to conduct his first experi- 

 ments in transatlantic wireless telegraphy, and 

 set up his temporary station on Signal Hill, at 

 the entrance of St. John's harbor. Previous to 

 leaving England he had arranged with his oper- 

 ators at the Poldhu station, upon receiving in- 

 structions, to send out daily, from 3 to 6 p. M. 

 Greenwich time (11.30 A.M. to 2.30 p. M. St. 

 John's time), the letter S of the Morse code 

 (...) as a signal. Upon his arrival he at once sent 

 up balloons and kites to which were attached the 

 aerial electrodes of his receiving apparatus. At 

 the beginning of the experiments his first balloon 

 broke away, and afterward he used only the kites. 

 One of these sent up Dec. 12 to a height of 400 

 feet remained there four hours. The signals w r ere 

 received from Poldhu and plainly distinguished, 

 repeated at intervals, beginning at 12.30 P. M. 

 and lasting irregularly for three minutes; resu- 

 ming at 1.10, and renewing at 2.20 for shorter in- 

 tervals, in all 25 times. 



As soon as his success was announced the 

 Anglo-American Cable Company, which holds a 

 monopoly from the Newfoundland Government, 

 declared that it would enforce its rights, and he 

 was compelled to go elsewhere to establish a per- 

 manent station. He finally chose Table Head, a 

 bleak promontory east of Glace Bay, Cape Breton 

 Island, and upon the assurance of the coopera- 

 tion of the Canadian and Nova Scotian govern- 

 ments at once began the erection of a station sim- 

 ilar to that at South Wellfleet, Cape Cod, Mass., 

 and later chosen for the plan of the new station 

 at Poldhu. In general they consist of 4 square 

 wooden towers, 28 feet across at the base, 9 to 1 1 

 feet across at the top, and 250 feet high. The 

 towers stand at the corners of a square, whose 

 sides are 210 feet long. Each one is cross-braced 

 with steel-wire rope. Then all 4 are connected 

 with each other by diagonal stays. Finally, to 

 render the structure still more rigid and wind- 

 proof, stout cables are run up over the tops of 

 each pair of towers on all sides, and secured to 

 anchorages in the earth. From each of the 4 hori- 

 zontal bridges which connect the tops of the tow- 

 ers are suspended 50 copper cables. The cables 

 are composed of 7 strands, an eighth of an inch 

 in diameter, tightly twisted together. The reason 

 for Uhing many fine strands instead of a few 

 large rods is to secure a larger amount of sur- 

 face for a given amount of copper. It will thus 

 be seen that the solitary " vertical wire " of the 

 original Marconi experiments has now been enor- 

 mously multiplied. Since the length of a Hertz 

 wave is four times the length of the vertical wire, 

 or antenna, waves not far from 860 feet (or a 

 sixth of a mile) long should be developed. This 

 corresponds to a frequency of about 1,100,000 a 

 second. The 50 oables of each of the 4 groups 

 converge a little as they go downward, and also 



incline slightly toward the center of the quadru- 

 plex edifice. The lower ends, therefore, are ar- 

 ranged along the sides of a square much smaller 

 than that formed by their supports at the top,, 

 and terminate in the operating-room of the sta- 

 tion. 



The distance from St. John's to Poldhu is 

 about 1,800 miles, and as the greatest distance, 

 up to that time, that Marconi had succeeded in 

 overcoming was about 60 miles, much doubt was 

 expressed as to the success of these experiments. 

 But even the most skeptical were convinced, when 

 on Feb. 25, 1902, and the day following, Mr. Mar- 

 coni, on board the steamship Philadelphia on his 

 way to America, received worded messages,, 

 certified by the ship's officers, up to a distance of 

 1551.5 miles and signals at a distance of 2,099- 

 miles. 



During the summer he continued his experi- 

 ments, his most notable achievements being the 

 exchanging of messages between Poldhu and the 

 Italian cruiser Carlo Alberta, in the harbor of 

 Cronstadt, Russia, in the presence of the Czar 

 and the King of Italy in July, a distance of about 

 1,400 miles; and a similar exchange between 

 Poldhu and Spezzia, Italy, in September. The- 

 King of Italy not only bestowed upon Mr. Mar- 

 coni many distinguished honors, but late in Sep- 

 tember granted him for six months, at the ex- 

 pense of the Government, the cruiser Carlo 

 Alberto for making wireless experiments. He- 

 arrived at the Cape Breton station, then nearing 

 completion, Oct. 31. The cruiser was in constant 

 communication with Poldhu during the voyage,, 

 and continued to receive messages after her ar- 

 rival in Sydney, Cape Breton, harbor; however,, 

 she was unable with her apparatus to send 

 messages farther than a few hundred miles. 

 After installing the machinery and sending and 

 receiving some experimental messages, on Dec. '21 

 the first official transatlantic wireless telegrams 

 were sent from Table Head. The messages were 

 from Lord Minto, Governor-General of Canada, 

 to King Edward VII of England, and from Mr. 

 Marconi to King Edward and to King Victor 

 Emmanuel of Italy, and from the commander of 

 the Carlo Alberto to the King of Italy, with other 

 minor messages. 



Mr. Marconi left Sydney for Cape Cod Jan. 14, 

 1903, arriving at the South Wellfleet station .Ian. 

 16, and on Jan. 18 sent direct from that station 

 to Poldhu, a distance of 3,000 miles, a message 

 from President Roosevelt to King Edward of 

 England. 



In place of the induction coils of his early ap- 

 paratus, Mr. Marconi used in these experiments 

 a transformer and a 40 horse-power, alternating 

 current dynamo. The transformer raises the 

 voltage from 2,000 to 20,000, and this is further 

 increased by means of condensers to from 50,000 

 to 70,000 volts. For the coherer he has substi- 

 tuted a " magnetic detector," connected with a 

 telephone receiver, which enables him to increase 

 greatly the speed of receiving, and consequently 

 of sending messages. To insure non-interference 

 he employs the tuning system invented by Prof. 

 Michael I. Pupin, of New York city, whose rights 

 he purchased in 1901. There has been much <lis- 

 cussion of the integrity of Marconi's so-called 

 inventions, and litigation is in progress over 

 many of the patents claimed by the various com- 

 panies interested in developing wireless teleg- 

 raphy. 



Marconi has now 35 or more stations in vari- 

 ous parts of the world, or about 70, including 

 those on ships. Of these, 12 land stations and 

 17 ships are fitted for sending commercial tele- 



