19i 



KNOWLEDGE. 



[September 1, 1900. 



over a long wire in one hour. This is over 1600 words 

 per minute. A column of the Times newspaper contains 

 a little over 2000 words. A page of this magazine, 

 without pictures, is about 1000 words. So this wonderful 

 telegraph apparatus could send nearly two pages of 

 this magazine in one minute, and at the same time, 

 print it on another receiving apparatus three or four 

 hundred miles distant. 



Some two years ago, Anton Pollak, a native of 

 Szentes, in Central Hungary, brought to the United 

 Electrical Company, of Buda Pesth, this untried system 

 of telegraphing at a high speed. The finn, after some 

 deliberation, set up a special laboratory for the purpose 

 of carrying out experiments, and seciu'ed the co-operation 

 of the well-known physicist and mechanician, Josef Virag. 

 The results of the experiments on an artificial wire were 

 so satisfactory that it was decided to test the apparatus on 

 a real working wire. By an arrangement with the State 

 telegraph officials, four wires were connected with the 

 laboratory of the Electrical Comjsany from the Central 

 Telegraph Office at Buda Pesth. These wires were in 

 turn connected from the Central Telegraph Office to 

 Temesvar, a town about 200 miles away. The ends of 

 the wires at Temesvar were joined together, and so, 

 although both the sending and receiving apparatus were 

 in the laboratory at Buda Pesth, the messages actually 

 passed over a wire of over 400 miles in length. In 

 order to test every condition the experiments were tried 

 first in fine dry weather and then in wet weather. 

 Copper wires were at one time used, at others iron wires. 

 The best results came from the use of copper wires, 

 but the results were always good. Over this wire of 

 400 miles in length, passing through open country, 

 messages were transmitted at the speed of 100,000 words 

 per hour. Even then the speed of the apparatus was 

 not at maximum. 



The fame of the apparatus having reached America, 

 Messrs. Pollak and Virag were invited to carry out some 

 experiments for the Western Union Company, and these 

 trials were attended with the most satisfactory and even 

 surprising results. In all cases the ordinary working 

 lines were used, and not only was the high speed of the 

 Hungarian experiments equalled, but in one notable 

 instance, over a wire from Chicago to Milwaukee, the 

 phenomenal speed of 155,000 words per hour was 

 attained. In very stormy and wet weather a trial was 

 made over the one thousand miles sepai-ating New York 

 from Chicago. Despite the unpi'opitious conditions 



prevailing a speed of G5,000 words per hour was attained 

 and maintained. The inventors express themselves 

 more than satisfied with this demonstration of the 

 practical commercial value of their invention. 



What is the mai-v'ellous apparatus which produces 

 this result? It is an ingenious combination of the 

 telegraph, the telephone, and photography. In order 

 to understand this extraordinary combination, which, 

 like all great inventions, is fundamentally simple, we 

 must know something of two electrical principles. 



First and most important comes the battery. The 

 battery is the generator and source of the electric 

 current. A battery is merely two plates of dissimilar 

 metal immersed in a bath of some chemical mixture — 

 the most common metals used being zinc and copper. 

 In order that a current may flow there must be a com- 

 plete path for it from the copper back to the zinc. 

 It is possible \a bury the wire which goes from one end, 

 or p(jle, of the battery in tlie eai'th, and if the end of 

 the other wire, which may be hundreds of miles away, 



be also buried in the earth the current will find its way 

 back. Now if we had a battery with the zinc end 

 wire buried in the earth, and the copper end wire joined 

 to another wire, which, some miles away, was buried 

 in the earth, a current would flow along the wire from 

 the battery, into the earth and back again, via the 

 other buried wire. If we turned the battery round 

 and joined the copper end to the buried wire, and the 

 zinc end to the wire which went to the distant station 

 before it was buried, we should have a current flowing 

 in the reverse direction, viz., into the earth, away to the 

 distant bui'ied end of the ti-unk wire, and back to the 

 battery by way of the trunk wire. This is the first 

 principle we must understand : that the dii-ection of the 

 flow of a cuiTent in a wire can be reversed by 

 reversing the connections of the battery. 



We must also be familiar with the action of the 

 current on a magnet. If we wind a piece of wire round 

 an iron nail and send a current of electricity through 

 the wire the nail becomes a magnet, with all the powers * 

 of a magnet to attract and repel. When the current 

 is stopped the nail ceases to be a magnet. When the 

 current is reversed the poles of the magnet ai-e also 

 reversed. If, however, we use an ordinai-y permanent 

 magnet instead of a piece of iron, we shall get the follow- 

 ing effect. Suppose we have a wire wound round the 

 north pole of a magnet, and pass through the wire 

 an electric current in the direction which would make 

 it a north pole magnet if it were a plain piece of iron. 

 The result is that the strength and attractive power is 

 increased. Now supjiose we reverse the direction of the 

 electric current, sending it in the direction which would 

 make a south pole magnet if we were dealing with a 

 plain piece of iron. The effect is to lessen or entirely 

 counteract the attractive jjower of the permanent mag- 

 net. This is the other principle we must understand — ■ 

 a current of electricity passed through a wire wound 

 round a permanent magnet will increase or decrease its 

 attractive power according to the direction of the 

 current. 



The apparatus by which the messages are sent is 

 really a device for changing the direction of the flow 

 of the electric current in the wire. The messages are 

 first prepared on a perforated pajier ribbon, which has 

 two rows of perforations. (Fig- 1-) The upper row 



9 «« •«• • e 



•• « AS O 9 ft**® 9* O d 



I, E, F, G, H, I, J, K. 



Fig. 1. — Photognipli of the perforations in the sending sWy of 

 the Pollak-Virag Tek'graph. The eentral line ol^ perforations 

 are fi>r gniding purposes. 



corresponds to the " dashes " of the Morse alphabet, 

 the lower row to the " clots." This ribbon is then 

 passed over a metal cylinder (Fig. 2) connected with the 

 wire which goes to the distant station. On the top of 

 the ribbon two little metal brushes press, one of which 

 is connected with the copper pole of the battery, and 

 the other with the zinc pole. When a perforation in 

 the paper ribbon passes under one of the brushes, the 

 brush touches the metal cylinder beneath, and a current 

 is sent. If one of the top row of holes passes, the 

 brush which is joined to the copper end of the battery 

 touches the cylinder, and a current flows along the wire 

 to the distant station, and back, through the earth, to 

 the zinc end of the battery. If one of the lower row 

 of holes passes, the bi-ush which is connected with the 

 zinc end of the battery touches the cylinder, and a 



