As Humboldt remarks, the resulting controversy, together with Acosta’s view that there were four lines of no variation which divided the earth’s surface, may, as already stated, have had some influence on the theory advanced, in 1683, by Edmund Halley, of four magnetic poles or points of convergence (“Cosmos,” 1859–1860, Vol. I. p. 193, note; Vol. II. pp. 280–281, note; Vol. V. p. 58; also Humboldt’s “Examen Critique de l’Histoire de la Géographie,” Vol. III. p. 60. See likewise the _Phil. Trans._ for October 19, 1668, p. 790, and for 1673, Vol. VIII. p. 6065, also following abridgments: Hutton, Vol. II. p. 78, and Lowthorp Vol. II. p. 610). REFERENCES.--Walker, “Magnetism,” Chap. I; John Pell, “Letter of Remarks on Gellibrand’s Math. Disc.,” 1635; “Annales de Chimie et de Physique,” Mars 1902, Vol. XXV. pp. 289–307; Humboldt, “Cosmos,” 1859, Vol. V. pp. 61, 116; Whewell, “Hist. of the Ind. Sc.,” 1859, Vol. II. p. 219; G. Hellmann, “Neudrucke von Schriften,” No. 9; Baddam’s abridgments of the _Phil. Trans._, 1739, Vol. IV. p. 102. =A.D. 1641.=--Wilkins (John), Bishop of Chester in the reign of Charles II, publishes the first edition of “Mercury, or the secret and swift messenger, showing how a man, with privacy and speed, may communicate his thoughts to a friend at any distance.”[44] In the above, he thus alludes to the possibility of making a contrivance similar to our modern phonograph: “There is another experiment ... mentioned by Walchius, who thinks it possible so to contrive a trunk or hollow pipe that it shall preserve the voice entirely for certain hours or days, so that a man may send his words to a friend instead of his writing. There being always a certain space of intermission, for the passage of the voice, betwixt its going into these cavities and its coming out; he conceives that if both ends were seasonably stopped, while the sound was in the midst, it would continue there till it had some vent. _Huic tubo verba nostra insusurremus, et cum probe munitur tabellario committamus_, etc. When the friend to whom it is sent shall receive and open it, the words shall come out distinctly, and in the same order wherein they were spoken. From such a contrivance as this [saith the same author] did Albertus Magnus make his Image, and Friar Bacon his Brazen Head, to utter certain words.” In the eighteenth chapter, he makes suggestions for “a language that may consist of only tunes and musical notes, without any articulate sound.” He had previously described a novel mode of telegraphing by the use of only three torches (or lights), to designate the twenty-four letters of the alphabet. These letters were, according to the plan of Joachimus Fortius, to be placed in three classes of eight each. One torch indicated Class I, two torches Class II, three torches Class III, and the number of the letter was shown by the number of times a torch was elevated.