moved along a pair of bar magnets (see fig. 10). A 

 year later Weber improved the moving coil mechani- 

 cally and combined the commutator with it. He also 

 added an alarm. 



Various combinations of left and right swings of the 

 needle up to four in number indicated the various 

 letters of the alphabet. Successive letters were indi- 

 cated by short pauses of the needle, and successive 

 words by longer pauses. The speed of transmission 

 was quite slow — only about seven letters per minute 

 could be sent, although initially only two letters per 

 minute could be sent. 



In 1835 officials of the Leipzig-Dresden railway 

 who saw the apparatus were so favorably impressed 

 by it that they considered installation of such a tele- 

 graph to control railway traffic. However, in spite 

 of Gauss' suggestion that possibly the tracks could be 

 used as part of the telegraph circuit, they finally 

 decided that the project would be too expensive. 

 The Gauss-Weber telegraph continued in operation 

 at the University of Gottingen until 1838, when 

 Weber was forced to leave the university because of 

 political difficulties and Gauss turned his attention 

 to other researches. 



In 1835, at the express invitation of Gauss, Prof. 

 Karl A. Steinheil of the Bavarian Academy of Sciences 

 began working on a simplified and more practical 

 version of Gauss and Weber's needle telegraph. After 

 making a number of changes, Steinheil completed his 

 apparatus (figs. 11-13) by 1836. The moving coil 

 inductor was replaced by a large magneto based on 

 Clarke's generator. The moving needle in the multi- 

 plier could be used in one of the following ways: to 

 strike against one of a pair of bells, each of a different 

 tone, or to ink dots on a recording tape. The various 

 combinations of tones, or dots, indicated acoustically, 

 in the case of the bells, or graphically, in the case 

 of the dots, the various letters of the alphabet.'^ 



The SteinheU telegraph was used successfully over 

 a long circuit. By July 1837 Steinheil had set up 

 three telegraph lines from the laboratory in the acad- 

 emy in Munich — one that extended 0.9 km. to his 



15 Karl Steinheil, "Ueber Steinheil's electro-magnetischen 

 Telegrapher! mit betrefFenden historischen Notizen," Dingters 

 polytechnisches Journal, 1838, vol. 67, pp. 388—391; "Notice sur le 

 telegraphe galvanique de M. Steinheil," Comptes rendtis, 1838, 

 vol. 7, pp. 590-593; "Beschreibung des galvano-magnetischen 

 Telegraphen zwischen Miinchcn und Bogenhausen, errichtet 

 im Jahre 1837," Dinglers polytechnisches Journal, 1838, vol. 70, 

 pp. 292-302; "Zum Andenken Steinheils," Archiv fiir Post 

 und Telegraphic, 1888, vol. 16, pp. 402-405. 



home, one that extended 0.1 km. to the shop of the 

 academy, and one that extended 5 km. to the astro- 

 nomical observatory. Each of these stations was con- 

 nected to the laboratory by a pair of copper or iron 

 wires strung on poles or buildings. A simple switch- 

 ing device at the central telegraph station in the lab- 

 oratory enabled Steinheil to connect any combination 

 of the four stations together. With this system he 

 was able to send about six words per minute. 



In 1838 the Bavarian government became inter- 

 ested in Steinheil's telegraph system, and a 5-mile line 

 along the Nurnberg-Fiirth railroad was proposed. 

 Steinheil tried to implement Gauss' suggestion of 

 using the railroad tracks in order to save some of the 

 expenses, but the difficulty in insulating the tracks 

 caused the plan to be abandoned. However, Stein- 

 heil's experiences showed him in June 1838 how he 

 could use the earth as one half of the telegraph line. 

 The ground return thus obtained reduced the instal- 

 lation and maintenance cost of the telegraph line con- 

 siderably. Steinheil's telegraph system worked so 

 well on the Niirnberg-Fiirth railroad that the Bavarian 

 government decided to try a line with a ground 

 return along a portion of the Munich-Augsburg rail- 

 road. However, the expense of installing the single 

 line was still too great, and the authorities decided 

 against the application of Steinheil's telegraph. 



Even before Gauss inspected Soemmerring's tele- 

 graph, it had been seen by Baron Pavel L. Schilling,'* 

 a member of the Russian embassy staff at Munich. 

 Schilling became a close friend of Soemmerring, and 

 it was Schilling who carried Soemmerring's telegraph 

 to St. Petersburg and a friend of Schilling who took 

 another model to Vienna to demonstrate it to Em- 

 peror Francis I. Schilling later worked out a needle 

 telegraph system, but it is difficult to determine when 

 this occurred, what were the construction details 

 of his first instruments, and how his code functioned. 

 J. Hamel, who knew Schilling personally, reported 

 that Czar Alexander, who died in 1825, had followed 

 Schilling's efforts to develop an electrical telegraph. 



16 Oken's Isis, 1836, vol. 29, col. 727; G. W. Muncke, article 

 "Telegraph," Gehler's physikalisches Woerterbuch, Leipzig, 1838, 

 vol. 9, pp. 100-126; J. Hamel, "Ueber die Erfindung des 

 elektromagnetischen Telegraphen durch Baron Schilling von 

 Canstatt und die Ueberfiihrung des neuen Apparates nach 

 England und Amerika," Gesellschaft deutscher Naturjorscher und 

 Aerzte, Berichte, 1857, vol. 33, pp. 60-65; Hamel, op. cit. (foot- 

 note 3); Auguste Guerout, "L'Historique de la telegraphic 

 electrique," La Lumiere electrique, 1883, vol. 8, pp. 332-339; 

 Feyerabend, op. cit. (footnote 13), pp. 17—22. 



284 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



