The history of telecommunications -Meucci page 090


		Antonio Meucci


		DOCUMENTS

		Advances on inductive load and its distribution along the line to the care of Eng. Basilio Catania

		This figure, extracted to affidavit of the English language Michael Lemmi with drawings and notes of Meucci dated 27 September 1870 [1], recently found at the National Archives in Washington DC [2] test Antonio Meucci realized that the effects of inductive load of telephone lines thirty years before the other pioneers of the phone [3-5].




		The schemes relate to experiments in long-distance transmission ( "long distance", as is indicated in the drawing No 1).

		I put in the middle of a wire conductor magnetized iron horse, with two bars, the two poles N and S, joined the conductor - gave me good satisfaction, but if the driver was copper, rather than iron, I think it would have been better (to be tested). "

		With reference to drawing No 2, , Meucci noted (re translation from):
		" By doing so will connect the center conductor of a big coil, putting in the middle of such a finger roll strongly magnetic iron, or put it before the tube to send with one of the poles, since the other pole in touch with the earth "

		Then, with reference to drawing No 3,Meucci continued:
		"The best method is to place the coil with magnetite - but the horseshoe is higher - the first of the instrument, which is receiver transmitter in order to receive electricity land, putting the conduit as shown by drawing No 4 . It works as if it were helped by galvanic battery. "

		And so concluded, referring to the plan No 4: The four schemes prove that Meucci had tried, in 1870, a route which, many years later, was called pupinizzazione of telephone lines. (The "pupinizzazione" makes it possible to achieve an increase in distance on equal quality phone, entering along the line, at certain intervals, appropriate inductances load).

		We must bear in mind that Meucci simulating the long distance with a roll of wire, and this had necessarily a remarkable capacity distributed and, therefore, took great advantage of the item inductive load. Note also, in the drawings shown in the figure, the return to earth of the telephone circuit, and in drawing No 4, the subdivision of the inductive load into two parts. It may be noted that in these drawings, which date back to 1870, the instruments used by telephone Meucci are shown schematically with their essentials (electromagnetic, diaphragm and acoustic cavity) encased in a tube.

		There are two other steps "Memorandum Book" Meucci prior to the earlier (respectively dated March 7, 1862 and May 20, 1862), but not accompanied by drawings; they cover the same topic and their understanding can be facilitated by the ' experiment of 27 September 1870. In particular, the complaint is the first of March 7, 1862 (p. 1 of the "Memorandum Book"). On the page number is derived from the Acts of the Bell / Globe [3], comparing the text of the "Memorandum Book" with Michael affidavit Lemmi (where the page numbers are not reported).

		his note refers to return to the land of telephone circuits and clarifies the design No 1 of the figure Here reported. So, in fact, noted Meucci: "By combining the two ends of the wire to land, it becomes a good conductor, taking the power of the earth, and goes long distance. Estremity ... the two who communicate with a hard metal in the ground, gave a very excellent result , communicating the power of the earth from one pole to another, and it is very simple ... " The second fact of Meucci (p. 2 of the "Memorandum Book") proves that he had discovered the advantages of the inductive load since 20 May 1862, when noted: "In the middle of the wire, a strongly magnetized iron protected by a roll does not need all of battery and is a good conductor of sound. It notes that if, as was argued by Judge Wallace, in agreement with the lawyers of the opposing party to Meucci, the transmission of sound was made by mechanics, rather than by electricity, the listing of an inducer halfway line had worsened and not improved the quality of transmission. On the other hand, the expression "conductor sound" was widely used, at the time, as synonymous with transfer sound (by electricity), so should not be interpreted as a conductor (mechanical) sound waves. In conclusion, since 20 May 1862, Meucci had noted that the quality of the line loaded inductive was so good that we could do without the battery, confirming that result with the experiment of 27 September 1870 and further improved by splitting the load . At the various processes that tend to establish the priorities to the invention of the telephone, no one realized the importance of Meucci notes on inductive load, simply because this technique was not known (See History of using inductive load) .


		[1] Affidavit of Michael Lemmi (Translation of Meucci's Memorandum book, sworn September 28, 1885. National Archives & Records Administration. College Park, MD-RG60, Year Files Enclosures 1885-6921, Box 10, Folder 1, 230/3/46/6. Catania B: An unpublished document reevaluates the work of Antonio Meucci. AEI, vol. AEI, vol. 82, n.2, 1995, p.128- 136. 82, No. 2, 1995, p.128-136. [3] Deposition of Antonio Meucci (New York, December 7, 1885 - January 1886), edition printed at the New York Public Library - Annex, New York. NY (USA) and original typescripts and manuscripts at the National Archives & Records Administration, New York, NY, edition: Records of the US Circuit Court, Southern District of New York, The American Bell Telephone Co.. et al. Et al. v. The Globe Telephone Co. V. The Globe Telephone Co.. et al. Et al. [4] Catania B: Antonio Meucci - requires a revision history. AEI, vol. AEI, vol. 85, n. 85, No 12, 1998, p. 12 1998, P. 906-914. 906-914. [5] Catania B: Four "Firsts" in Telephony (Letter). ETT , Vol. 10, No. 6, November-December 1999.

Antonio Meucci