Part 2 / Book 6 — Book VI (continued 10)

In the twenty-seventh volume of the Transactions of the London Society of Arts will be found the telegraphic devices of Knight Spencer and of Lieutenant James Spratt (pp. 20, 163–169), while the thirty-third volume contains (at pp. 23, 118–121) a description of the contrivance of Alexander Law, intended for service on both sea and land. These, it may be said, are the only additional telegraphic methods worthy of note introduced up to the time when the English Admiralty adopted the system proposed by Sir Home Popham in 1816. The “anthropo-telegraph” of Knight Spencer, though laid before the Society of Arts in 1808, had been used as early as 1805. It consisted merely of two circular discs of wicker work, painted white with a black circle in the centre, to be held in different positions with respect to each other. The device of Lieutenant Spratt was more simple still, for it consisted only in holding a kerchief in various positions; yet, simple as it was, it served as a means of communication between vessels before the battle of Trafalgar, and it was also successfully used to converse between Spithead and the ramparts at Portsmouth, etc.

References.—For Mr. Knight Spencer’s other papers, see the Philosophical Magazine, Vols. XXXVI. p. 321, and XL. p. 206, and, for different methods of telegraphing, see Mr. Macdonald’s “Treatise,” published in 1817, as well as, more particularly, Vols. XXVI, XXXIV, XXXV, XXXVI of the Transactions of the Society of Arts; likewise Rohde’s “Système complet de Signaux ...” published 1835.

A.D. 1808.—Callender—Calendar (Elisha), of Boston, Mass., obtains, on Oct. 3, 1808, for his lightning rod, an American patent, which latter is the first one in the line of electricity issued by the United States.

References.—H. L. Ellsworth’s “Digest of Patents,” Washington, 1840, p. 234; Edmund Burke, “A List of Patents,” Washington, 1847, p. 185; “List of United States Patents,” Washington, 1872, p. 67.

A.D. 1808.—Bucholz (Christoph—Christian—Friedrich), distinguished German chemist, receives his diploma as a physician at Rinteln, prior to graduating at the Erfurt University, and publishes “Ueber die Chimischen ... metallen,” giving a description of the chain bearing his name. The latter was the result of experiments made by him to prove that the electricity in the pile results from the oxidation of one of the metals and also to establish a comparison between the quantity of electricity obtained and the amount of oxygen absorbed by the one metal.

References.—“Biographie Universelle,” Bruxelles, 1843–1847, Vol. III. p. 227; A. F. Gehlen, Jour. für Chem. und Phys., Vol. V; L. Figuier, “Exp. et Hist.,” Paris, 1857, Vol. IV. p. 426; “La Grande Encyclopédie,” Vol. VIII. p. 315, and also the letter of J. B. Van Mons to Bucholz, Brussels, 1810.

A.D. 1808.—Amoretti (Carlo), Italian naturalist, who was allowed (1772) to withdraw from the order of St. Augustine that he might devote himself exclusively to scientific researches, gives, in his “Della rabdomanzia ossia elettrometria,” a complete history of the divining rod, and treats also therein of animal magnetism, etc. His investigations of the electric polarity of precious stones show, among other results, that the diamond, the garnet and the amethyst are - E, while the sapphire is + E.

References.—For a further account of the Virgula Divina, or divining rod (baguette divinatoire), see the “Gentleman’s Magazine” for 1751, Vol. XXI; also the notes at foot of pp. 91–106 of Baron Karl Von Reichenbach’s “Physico-Physiologicæ Researches,” translated by Dr. John Ashburner, London, 1851. In the latter, reference is made to Pierre Le Lorrain de Vallemont’s “La Physique Occulte,” etc. (1693), to a work written by Count J. de Tristan, to the “Mémoire,” etc., of Tardy de Montravel (1781) and to Pierre Thouvenel’s “Mémoires,” etc., the last named bearing the Paris-London imprint of 1781–1784, and attempting to show relations existing between the rod and electricity and magnetism. Allusion is likewise made in the afore-named work to the translation by Dr. Hutton (1803) of Jean Etienne Montucla’s (1778) improvement of Jacques Ozanam’s “Récréations Mathématiques et Physiques,” originally built upon Leurechon’s “Récréations Mathématiques,” and first published in Paris during the year 1724. For Reichenbach, see “Le Cosmos,” Nos. 703–705 for July 16, 23 and 30, 1898; “Cat. Sc. Pap. Roy. Soc.,” Vol. I. pp. 139–140; Vol. VIII. pp. 720, 721. Besides the above, reference should be had to the lecture of Prof. Rossiter W. Raymond before the Philadelphia Electrical Exhibition of 1884, and to the article in Paris Cosmos of Jan. 3, 1891, which alludes to the works of P. Lebrun (1702), Albert Fortis (1802), Dr. Charpignon (1848), Abbé Chevalier (1853), and M. E. Chevreul “De la baguette ...” (1854). Consult also, Eusebe Salverte, “The Philosophy of Magic.,” Vol. II. chap. xi. speaking of Pryce’s “Mineralogia Cornubiensis” (1778); Theod. Kirchmaier, “De Virgula divinatrice,” 1678; F. Soave, (Opus. Scelti, III. p. 253), 1780; F. M. Stella (Opus. Scelti, XIII. p. 427), 1790; G. B. San Martino (Opus. Scelti, XVII. p. 243), 1794; L. Sementini, “Pensieri e Sperimenti ...” 1811; A. M. Vassalli-Eandi (Opus. Scelti, XIX. pp. 215, etc.); Kiesser, Archiv., Vol. IV. p. 62; at Vol. I. p. 265, of Blavatsky’s “Isis Unveiled”; “Biographie Générale,” Vol. II. pp. 290, 291; “Roy. Soc. Catal. of Sc. Papers,” Vol. I. p. 58.

A.D. 1808.—Lebouvier-Desmortiers (Urbain René Thomas), French writer, who had called attention to the danger attending the bodily application of the galvanic fluid, through the Journal de Physique of 1801 (p. 467), transmits another Mémoire to the same publication upon an improved electrical (briquet) tinder box.

The cylinder, which had previously been made of copper, he constructed of glass as illustrated by Delaunay at Plate IX. fig. 105, of his “Manuel,” etc., Paris, 1809. With the new contrivance he was enabled to exert considerable force upon the piston, and it was generally necessary to push the latter suddenly in order to so compress the air as to light the (amadou) spunk attached to the lower portion of the cylinder.

References.—See his “Examen des principaux systèmes ...” Paris, 1813; J. C. Poggendorff, Biogr. Liter. Hand. ... Vol. I. p. 1399; Larousse, Dict. Univ., Vol. X. p. 290; Journal de Médecine, Vol. XXVI. pp. 298–303; Catal. Sc. Pap. Roy. Soc., Vol. III. p. 910; C. H. Wilkinson, “Elements of Galvanism,” London, 1804, Vol. I. p. 461; V. Delaunay, “Manuel de l’Electricité,” Paris, 1809, pp. 151–153; Detienne, “De l’électricité de pression” (Journal de Physique, 1777, Vol. IX).

A.D. 1809.—Krafft (Wolfgang Ludwig), Professor of Experimental Philosophy in the Imperial Academy of Sciences of St. Petersburg is the author of “Uber ein hypothet ...” wherein is given the result of his investigations of the phenomena of terrestrial magnetism.

Comparing Biot’s examination of the dip observations previously made by Humboldt, Krafft simplified the former’s conclusions, showing that if we measure the latitude from the magnetic equator, the tangent of the dip is double the tangent of such latitude, or, as he expresses it: “If we suppose a circle circumscribed about the earth, having the two extremities of the magnetic axis for its poles, and if we consider this circle as a magnetic equator, the tangent of the dip of the needle, in any magnetic latitude, will be equal to double the tangent of this latitude.”

Krafft gave a complete theory of the electrophorus in the first part of the 1778 “Acta Acad. Petrop.,” which latter also contains his experiments with Canton’s phosphorus and his observations on the aurora of February 6–17 of the same year. The results of many of his other investigations are to be found in Part XI of the work mentioned as well as in Vols. XV, XVII and XIX of the “Novi Commentarii Academiæ Petropolitanæ.”

A.D. 1809.—Pinkerton (John), gives in his “Voyages and Travels,” published at London (Vol. IV. pp. 1–76) a reprint of the rare volume entitled “Account of Paris at the close of the Seventeenth Century,” by Martin Lister, M.D., wherein are detailed several surprisingly interesting experiments made by Mr. Butterfield with his wonderful collection of loadstones. It is therein stated that one of these loadstones, when unshod, weighed less than a dram and would suspend a dram and a half, but when shod would attract 144 drams of iron, whilst another of the loadstones, weighing 65 grains, attracted 14 ounces, or 140 times its own weight; another would work through a wall eighteen inches in thickness, etc. etc.

A.D. 1809.—Children (John George), an English scientist to whom reference has already been made, more particularly under Cruikshanks, A.D. 1800, communicates to the Philosophical Transactions, “An account of some experiments performed with a view to ascertain the most advantageous method of constructing a voltaic apparatus for the purposes of chemical research.” This paper appears also in Vol. XXXIV of the Philosophical Magazine.

Four years later (1813) he publishes a description of his magnificent galvanic battery, the largest ever constructed on the plan suggested by Dr. Wollaston. This consisted of twenty pairs of copper and zinc plates, each six feet long and two feet eight inches wide, the united capacities of the cells being 945 gallons. With this battery he confirmed Davy’s observation that “intensity increases with the number (of plates) and the quantity of the electricity with the extent of surface.” It is reported that, when in full action, the battery rendered a platinum wire five feet six inches long and ¹¹⁄₁₀₀ of an inch in diameter red-hot throughout so as to be visible in full daylight; that eight feet six inches of platinum wire ⁴⁴⁄₁₀₀ of an inch in diameter were easily heated red; that a bar of platinum one-sixth of an inch square and two and a quarter inches long was heated red-hot and fused at the end; and that a round bar of the same metal, 276/1000 of an inch in diameter and two and a half inches long, was heated bright red throughout.

The result of many other investigations which he also made in 1813 and during 1815 showed that metallic wires (eight inches long and ¹⁄₃₀ of an inch diameter) became red-hot in the following order: platinum, iron, copper, gold, zinc, silver; and he deduced that their conducting power was in the inverse order, silver conducting best and platinum least. Tin and lead fused immediately at the point of contact, and the oxides of tungsten, uranium, cerium, titanium, iridium and molybdenum were also fused. An opening made with a saw across an iron wire having been filled with diamond powder, the diamond was liquefied and the contiguous iron became steel. (See the Pepys entry at A.D. 1802.)

References.—For Children’s other experiments, consult “Phil. Mag.,” Vol. XLII. p. 144; Vol. XLVI. pp. 409–415; Phil. Trans. for 1815, pp. 368–370, also Dr. Wm. Henry’s “Elem. of Exper. Chem.,” London, 1823, Vol. I. pp. 168–174; Dr. Thomas Thomson, “Outline of the Sciences,” London, 1830, pp. 524–526; Louis Figuier, “Expos. et Hist. ...” Paris, 1857, Vol. IV. pp. 389–390; Becquerel, Vol. I. p. 52; “Encycl. Metrop.,” Vol. IV. pp. 179, 222; Gmelin’s “Chemistry,” Vol. I. p. 424; “Cat. Sc. Papers Roy. Soc.,” Vol. I. p. 317; Vol. II. p. 26; “Bibl. Britan.,” Vol. XLIII, 1810, p. 67 and Vol. I of the N.S. for 1816, p. 109.

A.D. 1809–1810.—Oken (Lorenz)—originally Lorenz Ockenfuss—celebrated German naturalist, while occupying the post of Extraordinary Professor of Medicine at the University of Jena, publishes the great work “Lehrbuch der Naturphilosophie,” which was translated into English by Dr. A. Tulk and published in London, during 1847, by the Royal Society, under the title of “Elements of Physico-Philosophy.”

This work, says his biographer in the “English Cyclopædia” (Vol. IV. p. 557), takes the widest possible view of natural science: it is interesting as a document in the history of a great mental movement and contains the germs of those principles which are now regarded as the secure generalization of well-observed facts.

From the epitome of the work given in the “Encyclopædia Britannica,” the following is extracted: “Polarity is the first force which appears in the world.... Galvanism is the principle of life ... the vital force ... the galvanic process is one with the vital process.... There is no other vital force than the galvanic polarity.”

According to Dr. Richard Owen, Lorenz Oken contends that organism is galvanism residing in a thoroughly homogeneous mass. A galvanic pile, pounded into atoms, must become alive. In this manner, nature brings forth organic bodies. The basis of electricity is the air; of magnetism, metal; of chemism (the name he gives to the influence that produces chemical combination), salts. The basis of galvanism, in like manner, is the organic mass. Accordingly, whatever is organic is galvanic; whatever is alive is galvanic. Life, organism, galvanism, are one. Life is the vital process; the vital process is an organic or galvanic process. Galvanism is the basis of all the processes of the organic world.... God did not make man out of nothing, but took an elemental body then existing, an earth-clod or carbon, moulded it into form, thus making use of water, and breathed into it life, viz. air, whereby galvanism or the vital process arose.... Organization is produced by the co-operating process of light and heat. The ether imparts the substance, the heat the form, the light the life.... The life of an inorganic body is a threefold action of the three terrestrial elements, in which three processes galvanism consists. The nutrient process is magnetic, present and entire in every part of the body, and wheresoever it is withdrawn there is death.... These three processes constitute the galvanic process. Thus the galvanic circle is complete, and motion is the manipulation of galvanism. The process of motion is synonymous with the galvanic process—this is the vital process.

References.—The extended biography of Lorenz Oken, embracing a list of his chief works and original essays at pp. 498–503, Vol. XVI of the Eighth “Encycl. Britan.”; Dr. William Whewell’s “History of the Inductive Sciences,” 1859, Vol. II. p. 477; “Hist. des Sciences,” par F. L. M. Maupied, Paris, 1847, Vol. II. pp. 466–514.

A.D. 1809.—Luc (Jean André de), celebrated natural philosopher of Swiss extraction (though from 1773 until his death in 1817, a resident of England, where he became reader to Queen Charlotte, the consort of George III), transmits to the Royal Society a long paper treating of the separation of the chemical from the electrical effects of the pile, with a description of the electric column and aerial electroscope.

In this communication, says Dr. Young, he advanced opinions so little in unison with the latest discoveries of the day, especially with those of the President of the Royal Society, that the Council probably thought it would be either encouraging error or leading to controversy to admit them into the Philosophical Transactions. He had, indeed, on other occasions shown somewhat too much scepticism in the rejection of new facts; and he had never been convinced even of Mr. Cavendish’s all-important discovery of the composition of water.

The paper was afterwards published in Nicholson’s Journal (Vol. XXVI), and the dry column described in it was constructed by various experimental philosophers. It exhibited a continual vibrating motion, made sensible by the sound of a little bell, which was struck by the pendulum at each alternation; and during many months the vibration was more or less rapid, according to circumstances affecting the column.

This dry column consists of discs of Dutch gilt paper, alternated with similar discs of laminated zinc, so arranged that the order of succession will be maintained throughout. When sufficiently dry these are piled upon each other, the gilt side of the paper being in contact with the zinc, and all are pressed together in a glass tube by a brass cap and screw connected at each end with a metallic wire. The column presented by De Luc to the Royal Society consisted of 300 discs of zinc and of 300 discs of gilt paper. It is said that, with a larger column, the vibration of a brass ball suspended between two bells was so continued as to maintain a perpetual ringing for over two years; that with an apparatus comprising 20,000 groups of silver, zinc and double discs of writing paper, sparks have been obtained, while a Leyden jar was charged in ten minutes with sufficient electricity to produce shocks and to fuse an inch of platinum wire of an inch in diameter; and that a similar pile, in the Clarendon Laboratory at Oxford, rang ten small bells continuously for over forty years.

In Vols. XXXV, XXXVI and XXXVII of the “Phil. Mag.,” and in Vols. XXVII and XXVIII of “Nicholson’s Journal,” André de Luc shows how the dry column can be used for determining the insulating qualities and conducting power of bodies, it having been also employed as are aerial electroscopes to indicate the electrical changes taking place in the atmosphere. The other volumes of the same publications named below contain additional papers upon electricity, galvanism, etc., while at p. 392, Vol. L of the Phil. Mag. will be found an account of De Luc’s life and principal works, the latter being likewise mentioned in Vol. XXV of the “Biographie Universelle.”

References.—B. M. Forster, “Description ... elec. col. ... De Luc ...” London, 1810; Phil. Mag., Vol. XXXVII. p. 197; J. D. Maycock, Phil. Mag., Vol. XLVIII. pp. 165, 255; L. Configliachi, “Osservazioni sulle pile a secco”; M. Delezenne, “Expériences sur les piles sèches”; Bibl. Brit. Sci. et Arts, Vol. XLVII, 1811, pp. 3, 113, 213, 313; Vol. XLIX, 1812, pp. 88–92 (Necrology of J. A. De Luc), Vol. L, 1812, p. 351 (“Nicholson’s Journal,” No. 126), also the “Bibl. Britan.” for 1812, Vol. L. pp. 279–290 (Nicholson’s Journal, April 1812), for J. D. Maycock’s reply to De Luc’s objections concerning voltaic plates (“Phil. Mag.,” Vol. XLVIII. pp. 165, 255); Gmelin’s “Chemistry,” Vol. I. pp. 424–427; G. J. Singer’s “Elements of Electricity” and William Sturgeon’s Annals of Electricity, passim, as well as his “Researches,” Bury, 1850, pp. 147, 199, 261; De la Rive’s “Treatise on Electricity,” Vol. II. p. 852; Annales de Chimie et de Physique, Vol. II. pp. 79–82 for May 1816; Gilbert’s Annalen, Vol. XLIX; also Vols. VII, 1801, to Vol. LXXIV, 1821, for various articles upon the dry pile, etc.; G. Schübler, “Uber De Luc’s Elektr. saüle ...” 1813; Geo. Wilson’s “Life of Cavendish,” London, 1851, p. 66, etc.; “Nicholson’s Journal,” Vols. XXI, XXII, XXXII, XXXIII, XXXV; Phil. Mag., Vols. XLII, XLV, the last named containing, at pp. 359–363, Mr. G. J. Singer’s paper on “The Electric Column considered as ... first mover for Mechanical Purposes,” while at pp. 466, 467 is the communication of Mr. Francis Ronalds on De Luc’s electric column. The latter is also specially referred to in Vols. XLIII. pp. 241, 363; XLVI. p. 11; XLVII. pp. 47, 48; XLVIII. pp. 165, 255; LVII. pp. 446, 447; while at p. 55 of Vol. XLIX is a paper relative to a “combination of the electric column, the thermometer, barometer and hygrometer in one instrument, for electro-atmospherical researches.”

A.D. 1809.—Sömmering (Samuel Thomas von), German anatomist and physiologist, first employs voltaic, or contact, electricity for the transmission of telegraphic signals.

Both his original and perfected working instruments were constructed between July 9 and August 6, 1809 (Journal Franklin Institute, 1859, Vols. XXXVII and XXXVIII; Journal Society of Arts, Vol. VII. p. 235). The complete apparatus consists of thirty-five gold rods placed into glass tubes starting from a reservoir of acidulated water and connecting with thirty-five silk-covered wires, which are run into thirty-five apertures of copper (corresponding with twenty-five letters and ten figures) upon a wooden stand into each opening of which the wires of the voltaic pile can be inserted. When the latter are connected, the bubbles rising through the decomposition of the water are made to enter the lettered glass receivers through which the messages can be deciphered. On August 8, 1809, he was able to transmit intelligence a distance of 1000 feet, and twenty days later he presented his apparatus to the Bavarian Academy of Sciences (Fahie, “Hist. of Electric Telegraphy,” p. 228).

Sömmering’s telegraph was carried by Dominique Jean Larrey, chief surgeon of the French armies, to Paris, where it was delivered by him to the French Academy of Sciences, Dec. 5, 1809, and Dr. Hamel states that Biot, Carnot, Charles and Monge were appointed by that body to report upon the new invention (Journal of the Franklin Institute for 1859, Vol. XXXVIII. p. 398). In 1810 and 1811, Sömmering reduced the number of wires in his apparatus to twenty-seven. These brass or copper wires were first insulated with a covering of gum lac and then with silk thread, after which they were united into a thread-covered cable 1000 feet in length. The cable was in turn covered with heated gum lac or with a ribbon plunged in a solution of the same substance. The Russian Count Jeroslas Potocki took the new instrument to Vienna and submitted it, July 1, 1811, to the Emperor Francis I, while another model of the apparatus was sent to William Sömmering, then at Geneva, where it was shown to De la Rive, Auguste Pictet and other scientists. During March 1812 this instrument carried intelligence 10,000 feet, or ten times the distance previously reached.

References.—Dr. Hamel, Cooke’s reprint, pp. 7, 8. See Sömmering’s own description of this, the first electro-chemical telegraph, in “Der Elektrische,” etc., published by his son William at Frankfort, 1863, or the translations at p. 751 of Noad’s “Manual,” London, 1859, and at pp. 230–234 of Fahie’s “Hist, of Elec. Tel.,” London, 1884; Dr. Hamel, in Jour. Soc. of Arts, for 1859, p. 453, or the reprint of W. F. Cooke in 1859, Vol. VII. pp. 595–599 and 605–610; Du Moncel, “Exposé,” etc., Vol. III; Comptes Rendus, Tome VII for 1838, p. 81; “De Bow’s Review,” Vol. XXV. p. 551; Highton’s “Elec. Tel.,” p. 39; Harris, “Galvanism,” p. 35; Sturgeon’s Ann. of Elec., Vol. III, March 1839, pp. 447–448; “Turnbull, Electric Magn. Tel.” “Denkschr. Münch. Akad. ...” for 1809 and 1810, alluding to his first experimental instrument made in 1807; Schweigger, Journal, II. pp. 217, 240 of Vol. XX for 1817; Poggendorff’s Annalen, Vol. CVII. pp. 644–647; “Smithsonian Report” for 1878, pp. 269–271; Journal of the Franklin Institute for 1851, Vol. XXI. pp. 330–332; Prime’s “Life of Prof. Morse,” 1875, pp. 263–275; “Bibl. Britan.,” Vol. XLIX, 1812, p. 19; “Traité de tél. sous-marine,” E. Wünschendorff, Paris, 1888.

A.D. 1810.—Prechtl (Johann Joseph), German mathematician and chemist, director of the School of Arts and Navigation in Trieste, also professor in the Vienna Polytechnic Institute, is the author of several very interesting articles on electricity, magnetism, etc., which appeared in Gilbert’s Ann. der Physik from Vol. XXXV for 1810, to Vol. LXVIII for 1821, as well as in Gehlen’s Jour. für Chemie, Physik und Mineralogie, Vols. V-VII. According to Figuier (“Expos, et Hist. ...” 1857, Vol. IV. p. 433) we owe to Prof. Prechtl a still more lucid explanation of the theory of electric distribution and equilibrium in the voltaic pile than was conveyed even by the learned Prof. Jäger (A.D. 1802).

Of the many separate treatises which he wrote up to 1836, and which are contained in the numerous publications cited below, the most important, by far, is doubtless that treating of the fundamental state of the magnetic phenomena of the electrical connecting wire and on the transverse electrical charge (“Uber d. transversal-magnetismus ...”) which is to be found in Schweigger’s Journal für die Chemie und Physik, Vol. XXXVI. pp. 399–410, and in Dr. Thomas Thomson’s Annals of Philosophy, N.S., Article I. vol. iv. pp. 1–6 for July 1822. Alluding to the last named, Mr. Sturgeon says (“Scientific Researches,” Bury, 1850, p. 29) that an attempt is made by M. Prechtl to explain the manner in which the connecting wire acts upon the needle, but that his diagrams and his mode of reasoning are too complex to be entered into the “Researches.”

References.—Poggendorff’s “Biograph.-Liter. ...” Vol. II. pp. 519, 520; Larousse, “Dict. Univ.,” Vol. XIII. p. 45; “Catal. Sc. Papers Roy. Soc.,” Vol. V. pp. 3–5; Gehlen’s Journal, Vols. VII. pp. 141–282; VIII. pp. 297–318; Gilbert’s Annalen, Vols. XXXV, 1810, pp. 28–104; XLIV, 1813, pp. 108–111; LXVII, 1821, pp. 81–108, 221, 222, 259–276; LXVIII, 1821, pp. 104–106, 187–206; LXXVI, 1824, pp. 217–228; Brugnatelli’s “Giornale,” Vol. III, 1810, pp. 477–486; Kastner, “Archiv. Natur.,” II, 1824, pp. 151–167; Wien, “Jahrb. Pol. Inst.,” Vol. XIV, 1829, pp. 144–160, and Poggendorff’s Annalen der Physik und Chemie, Vol. XV, 1829, pp. 223–238.

A.D. 1810.—The compiler of this “Bibliographical History” will doubtless be pardoned for introducing here an additional mode of “communicating intelligence” promptly at great distances. Reference is made to the first germ of pneumatic telegraphy sown by the English engineer, George Medhurst, during the year 1810.

The London Telegraphic Journal, which gives an extract from the specification of Medhurst’s patent “for a new method of conveying letters and goods with great certainty and rapidity by air,” states that the process took practical form only in 1854, when Latimer Clark laid down a one-and-a-half-inch lead pipe between the Electric Telegraph Company’s central station, Lothbury, and the London Stock Exchange. The system was extended in 1858 to Mincing Lane, and, two years later, Varley introduced the use of compressed air, so that messages were drawn one way by a vacuum, and propelled in the opposite direction by a prenum, instead of employing a vacuum both ways, as Latimer Clark had previously done. During the year 1865 the system, then considerably modified, was introduced into Paris, and it was also made use of, at about the same time, by the Messrs. Siemens, who employed it between the Bourse and the telegraph station in the city of Berlin.

A.D. 1810.—Jacopi (Joseph), Italian physician, anatomist and physiologist (1774–1813), pupil of the famous Scarpa, makes known through his “Elementi di Fisiologia e Notomia comparata” (“Eléments de Physiologie et d’Anatomie comparée”), the results of his very extended investigations of the electrical organs of the torpedo.

To him is due the first clear description of the electrical lobes situated in the torpedo’s brain and of its relation to the eighth pair of nerves distributed throughout the hexagonal columns, which latter received also from him a very extended notice in the above-named work. The fifth ramification of nerves was first observed by Carus, and the most valuable investigation relative to the fourth and last important group of nerves directly connected with the electrical organs was made by the celebrated Italian professor, Carlo Matteucci.

References.—Larousse, “Dict. Univ.,” Vol. IX. p. 867; C. Matteucci, “Traité des Phénomènes Electro-Phys.,” Paris, 1844, pp. 283–318; Geoffroy St. Hilaire at A.D. 1803.

Another author, Delle Chiaje, likewise gave a description of the rhomboidal sinus-shaped protuberance which he calls lobo pagliarino (straw-coloured lobe), and which he considers as formed of one mass but does not admit its important connection with the electrical organs.

A.D. 1811.—Poisson (Siméon Denis), a very able French scientist, communicates to the “Institut des Mathématiques et Physiques” and publishes at Paris under the caption “Traité de Mécanique,” his analytical observations of the electric phenomena which, it has been truly said, actually establish a new branch of, and is the best elementary work extant upon, mathematical physics. One of his biographers remarks that Poisson’s object was “to leave no branch of physics unexplored by aid of the new and powerful methods of investigation which a school, yet more modern than that of Lagrange and Laplace, had added to the pure mathematics.”

As shown, notably by Sir David Brewster in his able article on “Electricity” in the eighth “Encycl. Brit.” (Vol. VIII. p. 531), and by Noad, in his “Manual” (London, 1859, pp. 15, 16):

“Poisson adopted as the basis of his investigations the theory of two fluids, proposed by Symmer and Dufay, with such modifications and additions as were suggested by the researches of Coulomb. He deduced theorems for determining the distribution of the electric fluid on the surfaces of two conducting spheres, when they are placed in contact or at any given distance, the truth of which had been established experimentally by Coulomb before the theorems themselves had been investigated. On bodies of elongated forms, or those which have edges, corners or points, it is shown as a consequence of the theory of two fluids that the electric fluid accumulates in greater depths about the edges, corners or points than in other places. Its expansive force, being therefore greater at such parts than elsewhere, exceeds the atmospheric pressure and escapes, while at other points of the surface it is retained.”

In the latter connection Mary Somerville remarks:

“There can hardly be a doubt but that all the phenomena of magnetism, like those of electricity, may be explained on the hypothesis of one ethereal fluid, which is condensed or redundant in the positive pole, and deficient in the negative; a theory that accords best with the simplicity and general nature of the laws of creation; nevertheless, Poisson has adopted the hypothesis of two extremely rare fluids, pervading all the particles of iron, and incapable of leaving them. Whether the particles of these fluids are coincident with the molecules of the iron, or that they only fill the interstices between them, is unknown and immaterial. But it is certain that the sum of all the magnetic molecules, added to the sum of all the spaces between them, whether occupied by matter or not, must be equal to the whole volume of the magnetic body.... M. Poisson has proved that the result of the action of all the magnetic elements of a magnetized body is a force equivalent to the action of a very thin stratum covering the whole surface of a body, and consisting of the two fluids—the austral and the boreal, occupying different parts of it; in other words, the attractions and repulsions externally exerted by a magnet are exactly the same as if they proceeded from a very thin stratum of each fluid occupying the surface only, both fluids being in equal quantities, and so distributed that their total action upon all the points in the interior of the body is equal to nothing. Since the resulting force is the difference of the two polarities, its intensity must be greatly inferior to that of either” (J. C. Wilcke at A.D. 1757, “Conn. of the Phys. Sci.,” 1846, s. 30 pp. 308, 309).

The “Mémoires de l’Institut” for 1811 contain Poisson’s very able papers showing the manner in which electricity is distributed on the surfaces of bodies of various figures and the thickness of the stratum of electricity existing throughout these bodies. Mrs. Somerville further observes of work already cited (s. 28):

“Although the distribution of the electric fluid has employed the eminent analytical talents of M. Poisson and M. Ivory, and though many of their computed phenomena have been confirmed by observation, yet recent experiments show that the subject is still involved in much difficulty. Electricity is entirely confined to the surface of bodies; or, if it does penetrate their substance, the depth is inappreciable; so that the quantity bodies are capable of receiving does not follow the proportion of their bulk, but depends principally upon the form and extent of surface over which it is spread; thus the exterior may be positively or negatively electric, while the interior is in a state of perfect neutrality.” (Consult J. Farrar, “Elem. of Elect. Magn. and Electro-Magn.,” 1826, pp. 50–56.)

In his treatment of the theories of magnetism, Brewster alludes again to the masterly investigations of Poisson, who, says he, appears to have been “the first to conceive the idea of absolute magnetic measurement.” In a short but luminous article at the end of the “Connaissance des Temps” for 1828, he describes the method for obtaining the value of H[** symbol] in absolute measure. His first and second “Mémoire sur la Théorie du Magnétisme” appeared during 1824–1825, at pp. 247, 488, Vol. V of the Transactions of the Paris Royal Academy, and were closely followed (Vol. VI. p. 441) by his Memoir on the theory of Magnetism in motion. Translations of these will be found at pp. 336–358, 373, Vol. I and pp. 328–330, Vol. V of the Edin. Jour. of Sci. and at pp. 334, 335 of John Farrar’s “Elem. of Elect. Magn. and Electro-Mag.,” all published during the year 1826.

Poisson’s theoretical prediction of magne-crystallic action is thus alluded to by Dr. John Tyndall in his “Researches on Diamagnetism,” etc., London, 1870, pp. 13 and 66, 67:

“In March 1851, Professor William Thomson (Lord Kelvin) drew attention to an exceedingly remarkable instance of theoretic foresight on the part of Poisson, with reference to the possibility of magne-crystallic action.

“Poisson,” says Sir William, “in his mathematical theory of magnetic induction founded on the hypothesis of magnetic fluids (moving within the infinitely small magnetic elements), of which he assumes magnetizable matter to be constituted, does not overlook the possibility of those magnetic elements being non-spherical and symmetrically arranged in crystalline matter, and he remarks that a finite spherical portion of such a substance would, when in the neighbourhood of a magnet, act differently according to the different positions into which it might be turned with its centre tube fixed. But (such a circumstance not having yet been observed), he excludes the consideration of the structure which would lead to it from his researches, and confines himself in his theory of magnetic induction to the case of matter consisting either of spherical magnetic elements or of non-symmetrically disposed elements of any forms. Now, however, when a recent discovery of Plucker’s has established the very circumstance, the observation of which was wanting to induce Poisson to enter upon a full treatment of the subject, the importance of working out a magnetical theory of magnetic induction is obvious.

“Sir William Thomson then proceeds to make the necessary ‘extension of Poisson’s Mathematical Theory of Magnetic Induction,’ and he publishes a striking quotation from the ‘Mémoires de l’Institut,’ 1821–1822, Paris, 1826.”

References.—Biography in “English Encycl.,” Vol. IV. p. 899; Phil. Mag. for 1851; Roy. Soc. Catal. of Sci. Papers, Vol. IV. pp. 964–969; G. M. Racagni, “Sopra una Memoria ...” 1839; Johnson’s “Encycl.,” 1878, Vol. III. p. 227; eighth “Britannica,” Vol. XV. p. 98; ninth “Britannica,” Vol. XV. pp. 241, 249; Ann. de Chimie for Feb. 1824; “Le Globe,” No. 87; Harris, “Magnetism,” p. 131; Whewell, “Hist. of the Inductive Sciences,” 1859, Vol. II. pp. 43, 208, 209, 222, 223; Sir William Thomson’s works, 1872; Thomas Thomson, “An Outline,” etc., 1830, p. 351; Mém. de l’Acad. des Sci. for 1824–1826, 1838; Soc. Philom. for 1803, 1824–1826; Humboldt’s “Cosmos,” London, 1849, Vol. I. pp. 104, 105, 130, 165–169; N. Bowditch, “Of a mistake which exists in the calculation of M. Poisson relative to the distribution of the electric matter upon the surfaces of two globes, in Vol. XII of the “Mém. ... Sc. Math. ... de France”; Mem. Amer. Acad., O.S., Vol. IV. part i. p. 307; Houzeau et Lancaster, “Bibl. Gén.,” Vol. II. p. 228. Mention is made of Poisson’s principal writings, in Vol. XI. pp. 179–191 of M. Max Marie’s “Hist. des Sciences Mathém.,” Paris, 1888, but the complete list will be found in Vol. II of the works of Arago.

A.D. 1811.—Schweigger (Johann Salomo Christoph), a chemist of Halle (1779–1857), inserts at p. 240, Vol. II of his Journal für die Chemie und Physik, the memoir of Sömmering, relative to his electro-chemical telegraph, as well as an appendix thereto, wherein he points out the difficulties likely to attend the employment of so many different wires. He suggests the use of but two wires, and of two piles of unequal power. With these, all desired characters could be transmitted, through a preconcerted code regarding the meaning of such letters and figures as would be represented by the weaker or the stronger pile, in conjunction with the duration of the gas evolutions or the space of time separating them. He also suggested, for an alarum, the use of a pistol, by connecting a battery to the pile, in lieu of liberating an alarm by means of accumulated gas as Sömmering had done.

Two months after Oersted’s great discovery, which was announced in July 1820, Schweigger read at Halle (September 16, 1820) and communicated to the German Literary Gazette (No. 296 for November 1820), a paper relative to an important improvement made in his galvano magnetic indicator. The latter, which had been described at pp. 206–208 of Gehlen’s (1808) Journal für Chemie, was merely an electroscope, employed to indicate the attraction and repulsion of ordinary frictional electricity in lieu of a Coulomb balance, the improved apparatus being the result of his discovery that, by coiling an insulated wire several times around a magnetic needle, the deflecting power of the voltaic current increases with the number of turns (Kuhn, “Ang. Elek.-Lehre,” p. 514).

Alluding to Schweigger’s multiplier, the Abbé Moigno says:

“A conducting wire twisted upon itself and forming one hundred turns will, when traversed by the same current, produce an effect one hundred times greater than a wire with a single turn: provided always that the electric fluid pass through circumvolutions of the wire without passing laterally from one contour to another” (Cornhill Magazine, Vol. II for 1860, pp. 61, 64).

It was, however, shown by Dr. Seebeck that the power of multiplication does not increase with the number of windings in the uniting wire, for the resistance to transmission naturally increases with the length of the wire, thus diminishing its conducting power.

To his new instrument Schweigger gave the name of electro-magnetic multiplier (multiplicator) or galvanometer multiplier, and it has become the most important for indicating and measuring the strength of the galvanic current.

Prof. W. B. Rogers says that Schweigger’s apparatus as improved by Nobili (Ital. Soc. Mem., Vol. XX. p. 173) became indispensable in the measurement of current electricity, and that through the later improvements given it by Sir William Thomson (also by Du Bois Reymond), it has been made one of the most perfect and delicate of all known means of measuring force. Schweigger’s multipliers with improvements made thereon by Oersted and Nobili are illustrated at p. 642, Vol. XXI of the eighth “Ency. Britannica,” where reference is made to drawings on a large scale shown at Plate 522, article “Thermo-Electricity,” of the “Edinburgh Encyclopædia.”

According to a footnote, p. 273 of “Report Smithsonian Inst.” for 1878, Schweigger’s multiplier is alluded to in the “Additions to Oersted’s Electroma-gnetic Experiments,” a memoir read at the Naturforschende Gesellschaft at Halle, September 16 and November 4, 1820. An abstract of this paper was published in the Allgemeine Literatur-Zeitung of Halle (4to), November 1820, No. 296, Vol. III. col. 621–624, whilst the full memoir appeared in the Journal für Chemie und Physik, 1821, Vol. XXXI. pp. 1–17; and “Additional Remarks ...” by Dr. Schweigger, in the same volume, pp. 35–41. It is further stated in the afore-mentioned note that:

“A galvanometer of somewhat different form, having a vertical helix and employing an unmagnetized needle, was very shortly afterward independently devised by Johann Christian Poggendorff, of Berlin; and as he preceded Schweigger in publishing an account of it, he is sometimes regarded as the original inventor. Schweigger designated his device an ‘Electro-magnetic Multiplicator’; Poggendorff designated his arrangement a ‘Galvano-magnetic Condensator.’ Prof. Oersted remarks: ‘Immediately after the discovery of electro-magnetism, M. Schweigger, professor at Halle, invented an apparatus admirably adapted for exhibiting by means of the magnetic needle the feeblest electric currents.... M. Poggendorff, a distinguished young savant, of Berlin, constructed an electro-magnetic multiplier very shortly after M. Schweigger, with which he made some striking experiments. M. Poggendorff’s work having been cited in a book on electro-magnetism by the celebrated M. Erman (published immediately after the discovery of these phenomena), became known to several philosophers before that of M. Schweigger’ (Annales de Chimie et de Physique, 1823, Vol. XXII. pp. 358–360).

“The researches of Schweigger and Bart leave us little or no doubt that the ancients were well acquainted with the mutual attraction of iron and the lodestone, as well as with the positive and negative properties of electricity, by whatever name they may have called it. The reciprocal magnetic relations to the planetary orbs, which are all magnets, was with them an accepted fact, and aerolites were not only called by them magnetic stones, but used in the Mysteries for purposes to which we now apply the magnet.”

References.—“Isis Unveiled,” Vol. I. pp. 281, 282. See also Annales de Chimie et de Physique, 1816, Vol. II. pp. 84, 86; Thos. Thomson, “An Outline of the Sciences ...” London, 1830, Chap. XV. p. 564; “Encycl. Brit.,” seventh edition, “Voltaic Electricity,” p. 687; Polytechnisches Centralblatt; Sc. Am. Supp., No. 404; Sturgeon’s “Scientific Researches,” Bury, 1850, p. 19; L. F. Kaemtz, Phil. Mag., Vol. LXII. p. 441; Poggendorff, Vol. II. pp. 873–875; Du Moncel, “Exposé ...” Vol. III; Whewell’s “Hist. of Ind. Sci.,” Vol. II. p. 251; “Abhandl. d. Naturf. Gesellsch. zu Halle” for 1853–1856; Schweigger’s Journal für Chemie und Physik, Vol. II. part iv. pp. 424–434; Vol. X for 1814 and Vol. XXXVIII for 1823; “Cat. Sc. Papers Roy. Soc.,” Vol. V. pp. 589–592; “Bibl. Britan.,” Vol. XVI, N.S., 1821, p. 197; Larousse, Vol. XIV. pp. 386–387. Edinburgh Philosophical Journal, July 1821, Vol. V. p. 113. For Seebeck, see Phil. Mag., Vol. LXI, 1823, p. 146. For Poggendorff, see “Cat. Sc. Pap. Roy. Soc.,” Vol. IV. pp. 952–956; Vol. VIII. pp. 638–640; “Bibl. Britan.,” Vol. XVIII, N.S., 1821, p. 195; Pogg., “Annalen,” Vol. CLX (biography).

In the editorship of Schweigger’s Journal, which followed Gehlen’s Journal, Mr. J. S. C. Schweigger was assisted, from 1828, by Franz W. Schweigger-Seidel, who was the author of “Lit. d. Math. Natur.,” published in 1828. (For the joint magnetic work of J. S. C. Schweigger and Wilhelm Pfaff, see Jour. f. Ch. u. Ph., Band X. heft i. for 1814.)

A.D. 1811.—Monsieur Dessaignes is first to establish a relation between electricity and phosphorescence, as is shown in the extract published in London from the Memoir which he had presented two years before to the French Institute. The general view he takes is that phosphorescence is produced by a particular fluid, which is set in motion by light, by heat, by electricity, as well as by friction, and that it is dissipated by overheating or by too long exposure to light.

It is asserted by Fahie (“Hist. of El. Tel.,” pp. xiv, 297) that it was Dessaignes and not Seebeck who first discovered thermo-electricity. “Dessaignes,” he says, “showed us how difference of temperature or heat could produce electricity.” This was in 1815, or six years before Seebeck, who is always credited with the observation (Bostock’s “History of Galvanism,” London, 1818, p. 101). Many observations bearing on thermo-electricity had been made even long before Dessaignes.... In 1759 Æpinus called attention to the same phenomena, and pointed out that electricity of opposite kinds was developed at opposite ends of the crystal (tourmaline). In 1760 Canton observed the same properties in the topaz; and between 1789 and 1791 Haüy showed the thermo-electric properties of various other substances, as mesotype, prehnite, Iceland spar, and boracite.

References.—Priestley’s “History of Electricity,” 1767, pp. 314–326. For Dessaignes’ other observations, see J. Farrar, “Elem. of Elec., Mag. and Electro-Mag.,” 1826, p. 125, and Phil. Mag., Vol. XLIV. p. 313. See also Phil. Mag., Vol. XXXVIII. p. 3; Journal des Mines, Vol. XXVII. p. 213; Poggendorff, Vol. I. p. 563; “Cat. Sci. Pap. Roy. Soc.,” Vol. II. pp. 272, 273; Chap. III. s. 3 of the “Electricity” article of the “Ency. Britannica.”

A.D. 1811.—The idea of placing a lightning conductor through the body of a ship is first suggested by Mr. Benjamin Cook, of Birmingham, and is carried out by Mr. William Snow Harris, of Plymouth. Mr. William Sturgeon, who mentions the fact (“Lectures of Electricity,” London, 1842, p. 208), adds that Mr. Harris “has formed the conductors into strips of copper, which are inserted in grooves in the after side of the masts from top to bottom and through the keelson to the sea. In one of the smaller men-of-war Mr. Harris carried his mizzen conductor through the powder magazine!!! The evils attending these conductors arise principally from lateral explosions and electro-magnetic influence.”

References.—For Wm. Sturgeon, consult Phil. Mag., Vol. XI, 1832, pp. 195, 270, 324; “Cat. Sc. Papers Roy. Soc.,” Vol. V. pp. 876–878, Vol. VI. p. 758 and Vol. VIII. p. 1042.

A.D. 1811–1812.—Schübler (Gustav), Professor, of Tübingen, is the first to present a connected series of observations upon the electricity of the air, which were made at Stuttgart, during all kinds of weather and at regular daily intervals, between May 1811 and June 1812. Other observations previously carried on by Schübler, during 1805 and subsequent years, at Ellvanguen and Stuttgart are detailed at pp. 579, 580, Vol. VIII—and are also alluded to in article “Meteorology”—of the eighth “Britannica.”

While De Lor was the first to observe, in 1752, the existence of electricity in the atmosphere, even when no lightning is visible, Schübler made the earliest known report upon the daily periodicity of the intensity of the electricity. The annual periodicity had been previously demonstrated by G. B. Beccaria, who published at Turin two able treatises on the subject during 1769 and 1775.

The origin of atmospheric electricity was, by Lavoisier, Laplace and Sir H. Davy, attributed in great part to the constant combustion taking place upon the earth’s surface. Volta and Saussure believed it to arise from the process of evaporation, while Pouillet pointed out the influence of the processes of vegetation; Reich, however, showed that as neither developed electricity they could not produce it in the atmosphere. Peltier advanced the theory that mere evaporation without chemical action is not enough, and the experiments of Faraday and Armstrong showed that evaporation without friction is likewise insufficient. These theories are treated of in “Gaea-Natur und Leben,” Köln and Leipzig, 1873, p. 322, and in Lardner’s “Popular Lectures,” 1859, Vol. II. pp. 149–160. The last named gives tables of many observations, and reports, among other matters, that the series of observations on the diurnal changes of atmospheric electricity which Schübler made, in 1811–1812, were repeated and confirmed at Paris in 1830 by M. Arago. During the month of March 1811 Schübler found that the mean time of the morning maximum was eight hours thirty minutes, and M. Arago ascertained the mean time for the same month to be eight hours forty-eight minutes.

References.—Edin. Jour. of Sci., new series, Vol. III; Biblio. Univers., Vol. XLII; Annales de Ch. et de Ph. for 1816, Vol. II. p. 85; “Jahrbuch der Ch. und Ph.,” 1829; Gilbert’s Annalen, Vols. XXXIX, XLIX, LI; Schweigger’s Journal, Vols. II. p. 377; III. p. 133; VIII. pp. 21, 22, 25, 26, 28, 29; IX. pp. 348, 350, 351; XV. p. 130; XIX. pp. 1 and 11; XXV. p. 249; XXXI. p. 39; Jour. de Phys., Vol. LXXV. p. 177; Vol. LXXXIII. p. 184; “Lehrbuch der Meteor,” L. F. Kaemtz, Halle, 1832, Vol. I. p. 337; Vol. II. pp. 411, 414; “Annual of Sc. Disc.” for 1862, pp. 99–103; L. Palmieri in Lum. Elec., Paris, Oct. 31, 1891, pp. 209–212; “Sci. Pap. Roy. Soc.,” Vol. V. pp. 559–562; Vol. VI. p. 755; “Bibl. Britan.,” Vol. II, N.S. for 1816 pp. 93–113 (atmosph. electricity); Poggendorff, Vol. II. p. 853; Report on Atmospheric Electricity by F. J. F. Duprez, 1858, Part III. chap. ii. pp. 363–368; Foggo, p. 124, Vol. IV of Edin. Jour. Sci.; J. J. Hemmer’s observations at Mannheim from 1783 to 1787, Lehrbuch, etc., Vol. II. p. 418, and the recorded investigations of De Luc, Girtannier, Mayer, Monge, Pouillet, Becquerel, De Tressan, Arago, De Saussure, Delezenne, Helwig and Kaemtz.

A.D. 1811.—In the first volume of his “Cosmos” (London, 1849, Vol. I. pp. 240–241) Humboldt speaks of islands of eruption, or marine volcanoes, which can properly be classed among electrical phenomena, and alludes to the one observed on the 13th of June 1811 by Captain Tillard (Tilland), and to which he gave the name “Sabrina.”

This volcano, which had previously appeared June 11, 1638 and December 31, 1719, off the island of St. Michael, in the Azores, is thus described in the Philosophical Transactions:

“Imagine,” says Captain Tillard, “an immense body of smoke rising from the sea, the surface of which was marked by the silver rippling of the waves occasioned by the slight and steady breezes incidental to those climates in summer. In a quiescent state, it had the appearance of a circular cloud, revolving on the water like a horizontal wheel, in various and irregular involutions, expanding itself gradually on the lee side, when suddenly a column of the blackest cinders, ashes, and stones, would shoot up in the form of a spire, rapidly succeeded by others, each acquiring greater velocity and breaking into various branches resembling a group of pines; these again forming themselves into festoons of white feathery smoke. During these bursts, the most vivid flashes of lightning continually issued from the densest portion of the volcano, and the columns rolled off in large masses of fleecy clouds, gradually expanding themselves before the wind, in a direction nearly horizontal, and drawing up a quantity of water spouts, which formed a striking addition to the scene. In less than an hour, a peak was visible, and, in three hours from the time of our arrival, the volcano then being four hours old, a crater was formed twenty feet high, and from four to five hundred feet in diameter. The eruptions were attended by a noise like the firing of cannon and musketry mixed; as also with shocks of earthquakes sufficient to throw down a large part of the cliff on which we stood.” (See description of the sudden appearance of the Island of St. Michael, etc., in Lectures by Dr. Webster, Professor of Chemistry and Mineralogy at Harvard College, Boston, 1822.)

A.D. 1811–1818.—Ure (Andrew), M.D., F.R.S., the first astronomer appointed to the Glasgow Observatory and the author of a Dictionary of Chemistry (the undisputed standard until the appearance of a similar work by Henry Watts), makes known the result of his electrical experiments in the same line as those made by Aldini (A.D. 1793) upon the body of a recently executed criminal. Noad, who gives a greatly detailed account of the investigations, at pp. 338–341 of his “Manual,” remarks that they “serve to convey a tolerably accurate idea of the wonderful physiological effects of the electrical agent, and will be impressive from their conveying the most terrific expressions of human passion and human agony.”

Dr. Ure is the inventor of an improved eudiometer, for detonating or exploding gases by means of an electric shock or spark, which is fully described and illustrated in the “Electricity” article of the “Britannica.”

References.—De la Rive, “Treatise on Electricity,” Vol. II. pp. 489–490, also “Encycl. Metropol.,” Vol. IV (Galv.), p. 197. Another report of Ure’s experiments appears at pp. 634, 635 of the “Encycl. Brit.,” article on “Voltaic Electricity,” also in No. 12 of the Journal Sci. and Arts, and at p. 56, Vol. LIII of the Philosophical Magazine.

A.D. 1812.—Through the New York Columbian, of July 1812, Mr. Christopher Colles informs the public that the operation of his new telegraphs “will be shown from the top of the Custom House on Tuesdays, Thursdays and Saturdays from four to six o’clock in the afternoon.”

In an explanatory pamphlet, he states that “eighty-four letters can be exhibited by this machine in five minutes, to the distance of one telegraphic station averaged at ten miles, and by the same proportion a distance of 2600 miles in fifteen minutes, twenty-eight seconds.”

James D. Reid, who mentions this fact at p. 5 of his “Telegraph in America,” says that the above was nothing but the already well-known European semaphore or visual signal, and that Colles worked his “machine” between New York and Sandy Hook for several years.

A.D. 1812.—On April 1 and 15, May 13 and June 17, Mr. M. Donovan, secretary of the Kirwanian Society of Dublin, reads before the latter body a long communication “On the Inadequacy of the Hypothesis at Present Received to Account for (explain) the Phenomena of Electricity,” which was afterward ably criticized by J. A. de Luc, as will be seen by reference to the Philosophical Magazine, Vols. XLV. pp. 97, 200, 329–332, and XLVI. pp. 13, 14. In his treatment of Eeles’ hypothesis (see A.D. 1755) Donovan gives some attention to the designed suppression by Priestley of Eeles’ valuable papers from the Philosophical Transactions.

The above communication was followed by still more valuable and much longer ones, read by Mr. Donovan before the same society, February 22, March 8, and March 22, 1815, entitled “On the Origin, Progress and Present State of Galvanism ... and Inadequacy of the Hypotheses to Explain Its Phenomena ...” a modified form of which obtained for its author the prize of the Irish Royal Society.

The sketch of the history of galvanism is divided into three periods. The first treats of the discoveries attaching to muscular contraction, and alludes to the observations of Sulzer, Galvani, Fabbroni, Humboldt, Pfaff, Fontana, Valli, Monro, Vassalli-Eandi, Fowler, Smuck, Marsigli, Grapengieser, Giulio, Rossi, Aldini and Wells. The second period reviews the gradual development of the physical and chemical power of combined galvanic arrangements, beginning with Nicholson and Carlisle, and refers to the many conclusions reached by Cruikshanks, Henry, Haldane, Ritter, Robertson, Brugnatelli, Fourcroy, Vauquelin, Thénard, Lehot, Trommsdorff, Simon, Helwige (Major Helvig), Twast, Bourguet, Erman, Grapengieser, Wollaston, Davy, Pfaff, Van Marum, Biot, Cuvier, Desormes, Bostock, Cuthbertson, Aldini, Lagrave, Jordan, Ritter and Wilkinson. The third period commences with the well-known generalizations of the chemical effects of galvanism made by Hisinger and Berzelius; their experiments on the invisible transfer of elements at a distance, and the explanation given by Grotthus of the invisible transfer of the elements of water. Following this, Donovan alludes to the announced decomposition of muriatic acid by W. Peel, Francis Pacchiani, and others, as well as the discovery of the source of mistakes in the Galvani Society investigations by Pfaff, Biot, Thénard and Davy; after which reference is made to the special observations of Sylvester, Grotthus, Wilson, Erman, Davy, Pontin, Gay-Lussac and Thénard, Children, De Luc, Singer, Murray and Maycock.

On the 5th of April 1815, Donovan reviewed the hypotheses of Volta and Fabbroni, as well as of the British philosophers Wollaston, Bostock and Davy, and, on the 19th of the same month, he read an additional paper on the inadequacy of the galvanic hypothesis, having previously (Dec. 28, 1814, and Jan. 11, 1815) presented to the Kirwanian Society a communication relative to a new theory of Galvanism.

References.—Phil. Mag., Vols. XXXIX. p. 396; XLIV. pp. 334, 401; XLV. pp. 154, 222, 308, 381; XLVI. p. 401; XLVII. pp. 167, 204; also Vol. XXXVII. pp. 227, 245, on Mr. Davy’s erroneous hypothesis of electro-chemical affinity, and Vols. XXII and XXIII of the Trans. Royal Irish Academy for Mr. Donovan’s papers relating to improvements in the construction of galvanometers, on galvanometric deflections, etc. etc.

A.D. 1812.—Zamboni (Giuseppe), Italian physicist, Professor of Natural Philosophy in the Verona Lyceum, makes known through his “Della pila elettrica a secco” an improved method of constructing dry piles. He dispenses entirely with the zinc plates of De Luc and employs only discs of paper having one side tinned and the other coated with a thin layer of black oxide of manganese pulverized in a mixture of flour and milk (“Note historique sur les piles sèches,” Annales de Chimie et de Physique, Vol. XI. p. 190).

His pile terminates in metallic plates, compressing the paper discs by means of silk ligatures, and the column is insulated by giving it a coating of either sulphur or shellac. In this apparatus the tinned surface is the positive element, the negative being the oxide of manganese, which replaces M. De Luc’s Dutch gilt paper. In the later forms of Zamboni’s pile the discs were formed of gilt and silvered paper pasted back to back. William Sturgeon remarks (“Scientific Researches,” Bury, 1850, p. 200) that the Zamboni piles are those which have been the most securely protected against the action of the ambient air and which alone have maintained their original electrical intensity.

References.—Larousse, “Dict. Univ.,” Vol. XV. p. 1452; K. F. Anton Von Schreibers in Gilbert’s Annalen, LV; Placidus Heinrich (Schweigger’s Journal, XV); Gustav Schübler, “Uber Zamboni’s Trockne Säule,” 1815–1816; G. F. Parrot (Gilbert’s Annalen, LV); K. C. F. Jäger in Gilbert’s Annalen, Vol. XLIX for 1815, pp. 47–66; De la Rive, “Treatise on Electricity,” Vol. II. p. 852; A. M. Ampère, Ann. de Chimie et de Phys., XXIX; John Farrar, “Elem. of Electricity,” etc., 1826, p. 179; Zamboni and Ambrogio Fusinieri, Ann. ... Reg. Lomb., Veneto, Vols. IV. pp. 128, 132; VI. pp. 31, 142, 143, 293; G. Resti-Ferrari, “Elettroscopio ... del Zamboni”; Ann. ... Reg. Lomb., Ven., Vols. II. p. 229; III. p. 290; “Verona Poligrafo” for 1831, p. 87; Mem. Soc. Ital., Vols. XXI, XXIII; Mem. dell’ Istit. Veneto, Vol. II. pp. 239, 251; G. A. Majocchi, Annali di Fisica, Vol. VIII. p. 14; “Comm. dell’ Ateneo di Brescia,” 1832, p. 38; Sturgeon’s “Researches,” Bury, 1850, pp. 147, 199, etc., for observations of A. de la Rive and Francis Watkins; Phil. Mag., Vol. XLV. pp. 67, 261; Ann. Ch. et Phys. for May 1816, Vol. II. pp. 76, etc., 82–87, and Bibl. Britan., Vol. LVII. p. 225; also Vol. LVIII. p. 111 of the O.S., Vol. II, N.S. for 1816, p. 21 as well as Vol. XL. p. 190; “Bibl. Univ.,” Bruxelles, 1831, Vol. XLVII. p. 183 (horloge électrique); “Edin. New Phil. Journal,” 1829, Vol. XXI. p. 357. See likewise the references at Hachette (A.D. 1803), Dyckhoff (A.D. 1804), Maréchaux (A.D. 1806), De Luc (A.D. 1809); the illustration and description of M. Palmieri’s dry pile in Sci. Am. Supp., Nos. 512, 519, and the accounts of investigations made more particularly by MM. Beetz, Belgrado, Burstyn, Crosse, Du Bois Reymond, De la Rive, D’Arsonval, Desruelles, Edelmann, Faraday, Gassiot, Gassner, Germain, Roul, Guérin, Haussman, Keiser, Schübler, Minotto, Pollak, Riess, Schmidt, Trouvé, Wagner, Watkins and Wolf.

A.D. 1812.—Schilling (Pawel Lwowitch), Baron (of Kannstadt), attaché to the Russian Embassy in Munich, and who had been two years before associated with S. T. Von Sömmering (Kuhn, p. 836), devises what he calls his “sub-aqueous galvanic conducting cord”—a copper wire insulated with a thin coating of india-rubber and varnish. This was laid both underground and under the sea, and, it is asserted that, by means of an arrangement of charcoal points, he was enabled to explode powder mines across the Neva, near St. Petersburg, as well as also across the Seine, during the occupation of Paris by the allied armies.

References.—Hamel, “Bull. Acad. Petersb.,” II and IV; also Wm. F. Cooke’s reprint, 1859, pp. 20–22; Fahie’s “History,” p. 309.

From the moment Schilling first saw the telegraph of Sömmering (Aug. 13, 1810) he made many experiments (Prime’s “Life of Morse,” p. 277) with the view of introducing it into Russia and finally took a model of it to St. Petersburg during the year 1812 (“Sc. Am. Suppl.,” No. 405). Hamel states (at p. 41 of Cooke’s reprint) that one of his contrivances was exhibited to the Emperor Alexander as early as 1825. Of this, Dr. E. N. Dickerson, in his Henry Memorial Address before Princeton College, gives the date as 1824. Be that as it may, it was only after his return from China in 1832 (two years after Sömmering’s death) that, following Ampère’s suggestion as to the availment of Oersted’s discovery, he submitted the apparatus which established for him the credit of having invented the electro-magnetic telegraph.

Many authors have erroneously described Schilling’s apparatus as consisting of a number of platinum wires insulated and bound together with a silken cord which put in motion thirty-six magnetic needles placed vertically in the centre of the multiplier by means of a species of key connecting with a galvanic pile. This account appeared at p. 43 of the “Journal des Travaux de l’Acad. de l’Industrie Française” for March 1839. The fact is that he employed but one magnetic needle and multiplier, with two leading wires, as proposed by Fechner, and was enabled by means of a combination of the deflections of the needle to the right and left to give all necessary signals for a complete correspondence by changing the poles of the battery at the ends of the wires. His call signal was given by a bell in connection with a clockwork, released by the deflection of a magnet.

References.—For a detailed explanation of the working of Schilling’s telegraph, J. S. T. Gehler’s “Physikalisches Wörterbuch” for 1838, Vol. IX. p. 111; Fahie’s “History,” pp. 310–313; “Sc. Am. Suppl.,” No. 405, p. 6467.

From the account of the telegraphic collection at the 1873 Exposition, published by Dr. Edward Zetzsche in the “Austellungblatte” of the Vienna “Neue Freie Presse,” the following is extracted: “Even after Prof. Oersted, of Copenhagen, had observed the deviation of a magnetic needle under the influence of the current, neither the proposition of Ampère, at Paris, in 1820 (of employing thirty needles and sixty wires) nor that of Fechner, at Leipzig, in 1829 (twenty-four needles and forty-eight wires) gave any impulse to telegraphy. Only in 1832 did the Russian Councillor of State, Baron Schilling de Kannstadt (who had seen the telegraph of his friend Sömmering, and had made it known in Russia), invent a new instrument with but five wires, which number he subsequently reduced to one. In it, the movements of the needle were rendered more perceptible by means of little discs of paper attached to a silk thread, holding the needle in suspension. This telegraph, it is true, was not put in application on a large scale, for Schilling died in 1837, but, on the 23rd of Sept. 1835, he had already brought out his apparatus at Bonn and at Frankfort-on-the-Main, where it was seen amongst other persons by Prof. Muncke, who doubtless constructed a similar one which he took with him to Heidelberg.”

It was only one year before his death that Schilling succeeded in obtaining the support of the Russian Government for his telegraph, and it was only after Muncke had shown it (March 6, 1836) to Wm. Fothergill Cooke, then a student in medicine at Heidelberg, that the latter produced his needle telegraph, which was followed by Cooke and Wheatstone’s still more perfect instrument in 1837 (Prime’s “Life of Morse,” pp. 265, 276). Some improvements in Schilling’s so-called deflective telegraph had, in the meantime, been made by Gauss and Weber at Göttingen, as well as by Steinheil at Munich.

Prior to his visiting Bonn (Meeting of Naturalists—Isis, Nog., 1836) Schilling had taken the working model of his telegraph to Vienna, where he made many experiments with it in conjunction with Baron Jacquin and with Prof. Andreas von Ettinghausen. Upon his return home from Germany in 1836, he declined invitations made him to bring his instruments to England (Dr. Hamel’s St. Petersburg lecture on “The Telegraph and Baron Paul Schilling”), whilst, by direction of the Russian Commission of Inquiry, he set up an experimental telegraph in two chambers of the Palace of the Admiralty connecting the apparatus by a long line over ground and by a cable laid in the waters of the canal. The results proved so satisfactory that in May 1837 the Emperor Nicholas ordered a submarine line to be laid between St. Petersburg and Cronstadt. Schilling’s death, on the 25th of July following, prevented, however, the execution of the project.

References.—Biography in Sci. Am. Supp., No. 547, p. 8737; Polytechnic Central Journal, Nos. 31, 32 for 1838; Lumière Electrique for March 17, 1883; “Allg. Bauztg.,” 1837, No. 52, p. 440; L. Turnbull, Electro. Magn. Tel. p. 223; (Hibbard’s Ev. 31; Channing, Ev. 41); Poggendorff, Vol. II. p. 798; Annales Télégraphiques for November to December 1861, p. 670; Journal Soc. of Arts for July 22, 1859, p. 598; References at Ronalds’ “Catalogue,” p. 457; Du Moncel, “Exposé,” Vol. III. p. 8 and “Traité Théorique et Pratique du Tel. Elect.,” Paris, 1864, p. 217; Comptes Rendus, Vol. VII for 1838, p. 82; Journal Franklin Inst. for 1851, p. 60; H. F. E. Lenz, “Uber die Praktische ... Galvanismus,” 1839; “Report of Smithsonian Inst.,” 1898, pp. 224–225.

A.D. 1812–1813.—Morichini (Domenico Pini), eminent Italian physician, is the first to announce that unmagnetized steel needles can be rendered magnetic by making the focus of violet solar rays collected through a lens pass repeatedly from the middle to one end of the needle, without touching the other half (Zantedeschi, II. p. 214).

The long contention created by this announcement and the ingenious experiments of Mrs. Somerville, together with the results obtained by P. T. Riess and L. Moser, are detailed at p. 48 of Brewster’s (1837) “Treatise on Magnetism.” At p. 12 of his article (Vol. XIV of the eighth “Britannica”), Sir David Brewster states that Morichini’s experiments were successfully repeated by both Dr. Carpi at Rome and the Marquis Ridolfi at Florence; but M. d’Hombre Firmas, at Alais, in France; Prof. Pietro Configliachi, of Pavia, and M. Berard, of Montpelier, failed in obtaining decided effects from the violet rays. In 1814 Morichini exhibited the actual experiment to Sir Humphry Davy, and in 1817 Dr. Carpi showed it to Prof. Playfair. A few months later Sir David Brewster met Davy at Geneva, and learned from him the fact that he had paid the most diligent attention to one of Morichini’s experiments, and that he had actually seen with his own eyes an unmagnetized needle rendered magnetic by violet light. Then follow in the same article the account of Dr. Carpi’s experiment as given to Brewster by Prof. Playfair, also details of the investigations of Mrs. Somerville, Mr. Christie, Sir William Snow Harris, Prof. Zantedeschi, of MM. Baumgartner and Barlocci, as well as those of Riess and Moser above alluded to.

References.—“Elogio storico del Cavaliere D. Morichini” in Mem. della Soc. Ital., Vol. XXVI. p. 3; Riess and Moser in Phil. Mag. or Annals, Vol. VIII. p. 155, 1830 and in Edin. Trans., Vol. X. p. 123; “Library of Useful Knowledge” (El. Mag.), p. 97; Zeitschrift, Vol. I. p. 263; Noad, “Manual,” pp. 532, 533; the article of Col. George Gibbs in Silliman’s Amer. Jour. of Sci., 1818, Vol. I. pp. 89, 90; Annales de Chimie, Vol. XLII. p. 304; Brewster’s “Optics,” p. 92; also articles “Optics,” p. 596, “Light,” p. 452 and “Electricity,” p. 569 of the eighth “Britannica”; Edin. Jour. of Sci., No. 4, p. 225; B. Gandolfi, “Antologia Romana,” 1797; Harris, “Rud. Mag.,” Parts I, II. p. 69; Phil. Trans. for 1826, pp. 132, 219; D. Olmstead, “Int. to Nat. Phil.,” 1835, Vol. II. p. 194. See also Thomas Thomson’s “Outline of the Sci.,” p. 514, and Berzelius’ “Traité de Chimie,” Vol. I. p. 138 for Morichini’s observations on galvanic energy; “Bibl. Brit.,” Vol. LII, 1813, p. 21; Vol. LIII, 1813, p. 195; Vol. LIV, 1813, p. 171 (Experiments of G. Babini in Florence); Vol. IV, N.S., 1817, pp. 1–8; Vol. V, N.S., 1817, p. 167; Vol. VI, N.S., 1817, p. 81; Vol. XI, N.S., 1819, p. 29 for the experiments of L. A. d’Hombre Firmas on Morichini’s violet rays, whilst p. 174 of the same issue gives J. Murray’s investigations as recorded in the “Phil. Mag.” for April 1819.

Peter (Pietro) Configliachi, already named, was the successor of Volta as Professor of Natural Philosophy at the Pavia University, and became editor of the “Biblioteca Fisica d’Europa,” the “Biblioteca Germanica,” the “Biblioteca Italiana” and the “Giornale di Fisica, Chimica e Storia Naturale” (Larousse, “Dict. Univ.,” Vol. IV. p. 908; J. J. Prechtl, in Schweigger’s Journal, Vol. IV for 1812; Fr. Mochetti, “Lettera al P. Configliachi,” Como, 1814; “Bibl. Britan.,” Vol. LVIII, 1815, p. 305 and Vol. IV of the N.S. for 1817, pp. 1–8).

A.D. 1813.—Sharpe (John Robert), of Doe Hill, near Alfreton, transmits to the Repertory of Arts a letter, which appeared in its Vol. XXIX, second series, p. 23, wherein he alludes to p. 188, Vol. XXIV of the same series, containing an account of Sömmering’s apparatus. He says:

“Without the slightest wish to throw a doubt over the originality of Mr. Sömmering’s invention, I beg leave to mention that an experiment, showing the advantages to be obtained from the application of the certain and rapid motion of the electric principle through an extensive voltaic circuit to the purpose of the ordinary telegraph, was exhibited by me before the Right Hon. the Lords of the Admiralty, in the beginning of February 1813.”

It is said that the Lords of the Admiralty spoke approvingly of it, but stated that as the war was over, and money scarce, they could not carry it into effect (Saturday Review for August 21, 1858, p. 190).

Ronalds says (“Catal.,” p. 473):

“No description of this telegraph appears to have been printed. It was mentioned at the Admiralty after the invention and full description of Sömmering’s, described fully and with figures in the Denkschriften of the Academy of Munich for 1809–1810, issued in 1811.”

Mr. Benjamin Sharpe, nephew of J. R. Sharpe, is the author of “A Treatise on the Construction and Submersion of Deep-Sea Electric Telegraph Cables,” London, 1861, wherein he alludes to the above, and asserts that his uncle “conveyed signals a distance of seven miles under water” (Fahie’s “History,” pp. 244–246; Sci. Am. Supp., No. 404, pp. 6, 446).

A.D. 1813.—Deleuze (Joseph Philippe François), French physician, publishes his “Histoire Critique du Magnétisme Animal,” containing the result of observations made by him during the previous twenty-five years upon animal magnetism.

According to Dr. Allen Thomson, of the University of Glasgow, Deleuze believed in the existence of an all-pervading magnetic fluid. This fluid, says he, is under the control of the will, and is constantly escaping from our bodies, forming around them an atmosphere, which, having no determinate current, does not act sensibly on the person near us; but, when urged and directed by our volition, it moves with all the force which we impress upon it; it is moved like the luminous rays emitted by substances in a state of combustion. The chief difference between the Deleuze and Puységur schools has reference to the various modes in which the magnetic fluid should be brought into action, and the suitable occasions for its employment.

During the year 1815 the Magnetic Society was established in Paris, with M. De Puységur as its president and M. Deleuze as vice-president, but it expired in 1820. In 1819 M. Deleuze had published his “Défense du Magnétisme Animal,” in reply to the attack made upon the subject by M. Virey through the “Dictionnaire des Sciences Médicales,” and he was followed, more particularly, by M. Bertrand, who issued in 1823 his “Traité du Somnambulisme,” and in 1826 his still more important work, “Du Magnétisme Animal en France,” etc. Respecting the last named Deleuze says:

“Of all the attacks directed against magnetism up to the present day, this is the most powerful, the most imposing, and the most ably combined. The author is a man of genius, etc. He has been occupied with magnetism for some years. He has joined its practice to that of medicine, and he has even taught its doctrines in public lectures. A more attentive examination and new experiments have dissuaded him from a belief which he himself propagated; he undertakes to undeceive others, and to prove that magnetism is a mere chimera. Certainly his conviction must be very strong.”

References.—Article “Somnambulism,” in the “Britannica,” more especially for a review of, and extracts from, Deleuze’s great work, also the translation of the latter by T. C. Hartshorn, of which the enlarged fourth edition was published at London in 1850, accompanied by notes and a life by Dr. Foissac.

A.D. 1813.—Brande (William Thomas), F.R.S., succeeds Sir Humphry Davy as Professor of Chemistry to the Royal Institution after having long been his assistant.

He was already favourably known through a long line of interesting chemical experiments, one of which, treating of the effects of the galvanic current on albumen, had attracted very particular attention at the time it was communicated to the Philosophical Transactions. When he applied Davy’s method to fluids containing albumen, the albumen and acid were found at the positive pole and the albumen and alkali at the negative pole, and he also observed that, although it remained fluid with a weak battery, a stronger one caused it to be separated in a coagulated form. In like experiments subsequently made by Golding Bird, coagulation took place in the positive vessel, while none occurred in the negative; after a time the contents of the former had an acid taste, and of the latter a caustic alkaline flavour. When all in the positive vessel was coagulated by the galvanic action, he found there hydrochloric acid mixed with chlorine and the alkali in the negative vessel.

He also repeated the experiments of Davy on the light developed by charcoal points connected with a powerful galvanic battery, and found that this light was as effectual as solar light in decomposing muriate of silver and other bodies, and in acting upon hydrogen and chlorine gases, causing them to detonate, but he could not produce the same effect by the moon’s rays or by any other light.

The electricity developed in flame, which had received much attention from Paul Erman and others, was likewise investigated by Prof. Brande, whose conclusions are to be found detailed at Sec. III. chap. iii. part i. of the “Electricity” article in the “Encyclopædia Britannica.” Therein is recalled the fact that A. L. Lavoisier, P. S. Laplace and Aless. Volta previously obtained clear indications of electricity by the combustion of charcoal, while H. B. de Saussure failed to develop electricity either by the combustion or explosion of gunpowder, and Humphry Davy could not obtain it through the combustion of charcoal or of iron in air or in pure oxygen. In the above-named article will also be found an account of the investigations of Pouillet and of Becquerel in the same line; some of the other well-known scientists who have treated more or less directly upon the subject being E. F. Dutour, J. S. Waitz, J. J. Hemmer, Heinrich Buff, G. Gurney, Carlo Matteucci, W. R. Grove, Michael Faraday, M. A. Bancalari, W. G. Hankel, F. Zantedeschi and M. Neyreneuf.

References.—Phil. Mag., Vol. XLIV. p. 124; Phil. Mag. or Annals, Vol. IX. p. 237; Annales de Chimie, 5^e série, Vol. II; Phil. Trans. for 1809 and 1820; Mémoires de Mathématiques, Vol. II. p. 246; “Cat. Sc. Pap. Roy. Soc.,” Vol. I. p. 48; “Bibl. Britan.,” Vol. LVII, 1814, p. 11.

A.D. 1813.—Colonel Mark Beaufoy (already alluded to at Graham, A.D. 1722), describes in the first volume of Dr. Thomas Thomson’s Annals of Philosophy what has by many been called the most perfect form known of the variation compass. It is also to be found illustrated at p. 81, Vol. XIV of the eighth “Britannica,” wherein it is said that he employed it in the valuable series of magnetic observations made by him between the years 1813 and 1821. It consists of a telescope, underneath the axis of which is a magnetic needle whose position is alterable in order to indicate the exact angle of deviation, or the declination of the needle from the true meridian.

Brewster states (eighth “Brit.,” Vol. XIV. p. 54) that when the diurnal variation of the needle was first discovered it was supposed to have only two changes in its movements during the day. About 7 a.m. its north end began to deviate to the west, and about 2 p.m. it reached its maximum westerly deviation. It then returned to the eastward to its first position, and remained stationary till it again resumed its westerly course in the following morning. When magnetic observations became more accurate, it was found that the diurnal movement commences much earlier than 7 a.m., but its motion is to the east. At 7.30 a.m. it reaches its greatest easterly deviation, and then begins its movement to the west till 2 p.m. It then returns to the eastward till the evening, when it has again a slight westerly motion; and in the course of the night, or early in the morning, it reaches the point from which it set out twenty-four hours before. The most accurate observations made in England were those of Colonel Beaufoy, when the variation was about 24½´ west. In these the absolute maxima were earlier than in Canton’s observations, and the second maximum west about 11 p.m. Dr. Thomas Thomson alludes to the diurnal investigations of Barlow and Christie and others, and gives (“Outline of the Sciences,” London, 1830, pp. 543–550) a table of the mean monthly variation of the compass from April 1817 to March 1819 as determined by Colonel Beaufoy. Mr. Peter Barlow, he says, has given in his “Essay on Magnetic Attractions” a very ingenious and plausible explanation of the daily variation by supposing the sun to possess a certain magnetic action on the needle.

References.—Phil. Mag., Vol. LIII, 1819, p. 387; LV, 1820, p. 394; W. S. Harris, “Rud. Mag.,” Parts I, II, pp. 150–152; “Encycl. Metrop.,” Vol. III (Magnetism), pp. 766, 767; Annals of Phil., series 1, Vols. II, VI, IX, XVI, and N.S., Vol. I. p. 94, for Beaufoy’s own summary of all his observations.

A.D. 1814.—Mr. Thomas Howldy addresses to the Philosophical Magazine a letter, dated Hereford, March 24, 1814, relative to “Experiments evincing the influence of atmospheric moisture on an electric column composed of 1000 discs of zinc and silver,” wherein he also makes reference to the dry pile of J. A. De Luc alluded to at A.D. 1809.

References.—Phil. Mag., Vol. XLIII. pp. 241, 363, and Nicholson’s Journal, Vol. XXXV. p. 84; also the Phil. Mag., Vol. XLI. p. 393, for a description of the electric column of 20,000 pairs of zinc and silver plates, and others, constructed during the previous year (1813) by Mr. George J. Singer.

The above-named letter was followed (Phil. Mag., Vols. XLVI. pp. 401–408, and XLVII. p. 285) by a communication on the “Franklinian Theory of the Leyden Jar ... with Some Remarks on Mr. Donovan’s Experiments,” and by another letter sent to MM. R. Taylor and R. Phillips (Phil. Mag. or Annals, Vol. I. p. 343) relative to the paper of William Sturgeon “On the Inflammation of Gunpowder by Electricity,” which appeared at p. 20 of the last-named book.

An interchange of correspondence not long since through the columns of the London Electrical Review, for the purpose of ascertaining the period of the earliest use of carbon as a resistant, brought forth an extract from the “Treatise on Atmospheric Electricity,” published at London and Edinburgh, 1830, by Mr. John Murray, of Glasgow, which reads as follows: “Mr. Howldy, of Hereford, an ingenious electrician, has by some novel experiments clearly proved the increased power of electricity if retarded in its progress; instead of using tubes of glass filled with water, as Mr. Woodward had done, he has employed a glass tube supplied with lamp black.”

A.D. 1814.—Murray (John), Scotch physician and chemist, also Ph.D., and Professor of Chemistry and Materia Medica in the Edinburgh University, is the author of works entitled, “On Electrical Phenomena, and on the new substance called Jod (Iode),” also “On the Phenomena of Electricity,” published at London, respectively, during the years 1814 and 1815 (Tilloch’s Phil. Mag., Vols. XLIII. pp. 270–272; XLV. pp. 38–41; “Catalogue Sci. Pap. Roy. Soc.,” Vol. IV. pp. 556–557).

Dr. John Murray died July 22, 1820, in Edinburgh, the place of his birth, as will be seen by reference to Larousse, “Dict. Univ.,” Vol. XI. p. 706, and to Poggendorff, Vol. II. pp. 243, 244. He should not be confounded, as has been done by many, with Mr. John Murray, whose papers, read before the Royal Society (“Catalogue Scientific Papers,” Vol. IV. pp. 557–559; Vol. VI. p. 731), treat of the relations of caloric to magnetism, of the unequal distribution of caloric in voltaic action, etc., of aerolites, of the decomposition of metallic salts by the magnet, of the ignition of wires by the galvanic battery, of lightning rods, conductors, etc. (These papers appear in Tilloch’s Phil. Mag., Vols. LIV, 1819, pp. 39–43; LVIII, 1821, pp. 380–382; LX, 1822, pp. 358–361; LXI, 1823, p. 207; LXII, 1823, p. 74; LXIII, 1824, pp. 130, 131; L. F. von Froriep, “Notizen ...” for 1823, Vol. IV. col. 198; Edin. Phil. Jour., Vols. XIV for 1826, pp. 57–62; XVIII for 1828, pp. 88–91; and in Sturgeon’s Annals, Vols. III for 1838–1839, pp. 64–68; VII for 1841, pp. 82–83.)

Mr. John Murray is said to have been a lecturer on experimental philosophy, and one of his most interesting reviews is the one appearing at p. 62, Vol. XLIII of the Phil. Mag. regarding Ezekiel Walker’s theory of combustion as deduced from galvanic phenomena. Murray thinks there is much obscurity in Mr. Walker’s solution, which arises “from his using indiscriminately the terms heat (caloric) and combustion. Now caloric (the matter of heat) and combustion (the act of ignition) are not identical. What may be collected, however, from the general tenor of that paper is the theory of Lavoisier in a new dress.”

At p. 17 of this same volume is a paper from Mr. John Webster on the agency of electricity in contributing the peculiar properties of bodies and producing combustion, while, at p. 20, is a letter from Mr. George J. Singer wherein he calls Mr. Walker a novice in the science of electricity, saying that among other things he “has yet to learn that a conducting body supported by dry glass and surrounded by dry air may be still very far from being insulated.”

The treatise of Mr. John Murray on “Atmospheric Electricity” previously alluded to (at Thomas Howldy, A.D. 1814) was translated into French (“Mém. de l’Elec. Atm.”) by J. R. D. Riffault, Paris, 1831.

References.—Phil. Mag., Vols. XLIII. p. 175; L. pp. 145, 312; LII. p. 60; LIII. pp. 268, 468; LVIII. p. 387; LX. p. 61; LXI. p. 394; LXII. p. 456; LXIII. p. 130; also pp. 306, 307 of Fahie’s “History,” regarding John Murray’s “Notes to Assist the Memory in Various Sciences.”

A.D. 1814.—Wedgwood (Ralph), member of the family whose name is inseparably connected with one of the most beautiful manufactures of pottery, completes an electric telegraph, upon which he has been steadily at work from 1806. Of its construction or mode of action he appears, however, to have left no particulars.

At pp. 178 and 180 of “The Wedgwoods ...” by Llewellyn Jewett, London, 1865, appears the following:

“This Thomas Wedgwood was, I believe, cousin to Josiah, being son of Aaron Wedgwood, etc., etc. ... He was a man of high scientific attainments, and has the reputation of being the first inventor of the electric telegraph (afterward so ably carried out by his son Ralph) and of many other valuable works.... In 1806 Ralph Wedgwood established himself at Charing Cross, and soon afterward his whole attention began to be engrossed with his scheme of the electric telegraph, which in the then unsettled state of the kingdom—in the midst of war, it must be remembered—he considered would be of the utmost importance to the government. In 1814, having perfected his scheme, he submitted his proposals to Lord Castlereagh, and most anxiously waited the result ... was informed that ‘the war being at an end, the old system was sufficient for the country.’ The plan, therefore, fell to the ground, until Prof. Wheatstone, in happier and more enlightened times, again brought up the subject with such eminent success. The plan thus brought forward by Ralph Wedgwood, in 1814, and of which, as I have stated, he received the first idea from his father, was described by him in a pamphlet, entitled ‘An Address to the Public on the Advantages of a Proposed Introduction of the Stylographic Principle of Writing Into General Use; And Also an Improved Species of Telegraphy, Calculated for the Use of the Public, as Well as for the Government.’”

The pamphlet is dated May 29, 1815. Fahie gives (“History,” pp. 125–127) extracts both from this pamphlet, regarding the electric Fulguri-Polygraph, and from the communication of Mr. W. R. Wedgwood to the Commercial Magazine for December 1846, urging his father’s claims to a share in the discovery of the electric telegraph.

References.—“Life of Wedgwood,” by Miss Meteyard, 2 vols., 1865–1866; J. D. Reid, “The Telegraph in America,” p. 70.

A.D. 1814.—Singer (George John), distinguished English scientist and writer, publishes the first edition of his valuable “Elements of Electricity and Electro-Chemistry,” of which translations were made, in French by M. Thillaye, Paris, 1817, as well as in German and in Italian during the year 1819.

Mr. Singer is the inventor of the improvement upon Mr. Bennet’s electroscope, which is to be found illustrated and described in nearly all works upon natural philosophy and the main design of which is to diminish, if not totally prevent, the amount of moisture generally precipitated upon the surface of insulators. Mr. Singer remarks that his arrangement so effectually precludes moisture that some of the “electrometers constructed in 1810 and which have never yet (1814) been warmed or wiped, have still apparently the same insulating power as at first.” The use of this apparatus is strongly recommended by Dr. Faraday, whose instructions for the use of electrometers are given at great length at pp. 617–619, Vol. VIII of the eighth “Britannica.”

After describing the above-named electrometer, Mr. William Sturgeon remarks (“Lectures,” London, 1842, pp. 42, 43):

“It is frequently exceedingly difficult, without extensive reading, to confer the merit that is due to invention on the right party, and even then we sometimes err for want of proper information. Mr. Singer has hitherto, with most writers, had the exclusive merit of insulating the axial wire of the electroscope from the brass cap, by a glass tube; and it would appear from the description he gives of this improvement in his excellent treatise on electricity that he was not aware of anything of the kind being previously done. It appears, however, by an article of Mr. Erman in the Journal de Physique, Vol. LIX. p. 98, and Nicholson’s Journal, Vol. X, published in 1805, that a Mr. Weiss had applied the glass tube for the purpose of insulating the axial wire of Bennet’s electroscope. The account runs thus: ‘The electrometer he (Mr. Erman) used was that distinguished in Germany as the electrometer of Weiss.’ From this it would appear to have been long known. ‘The length of its leaves of gold is half an inch, and the diameter of the glass cylinder which encloses them is three-quarters of an inch, the height being an inch and a half. Its cover of ivory does not project above the glass, and is perforated in the middle with a hole in which a smaller glass tube is fixed, and through this last tube passes the metallic rod that serves to suspend the gold leaves.’ Singer’s improvement, first published in 1814, would, therefore, consist in adding the brass ferrule, which covers the glass tube first introduced by Weiss.”

Singer is also the inventor of one of the best-known amalgams for the cushions of the electric machine. It is described at p. 536, Vol. VIII of the eighth “Britannica,” where it is said that a mixture of one part tin and two parts mercury is very effective, as is also the amalgam consisting of mosaic gold and the deutosulphuret of tin. (Other descriptions of the application of mosaic gold on the rubber are to be found at p. 432, Vol. II of “Young’s Course of Lectures”; Woulfe, Phil. Trans., 1771, p. 114; Bienvenu and Witry de Abt, Lichtenb. Mag., Vols. II. p. 211, and IV. st. 3, pp. 58–61; Marquis de Bouillon, “Observ. de Physique,” XXI.)

The dry electric columns which Mr. Singer invented are alluded to in Phil. Mag., Vols. XLI. p. 393 and XLV. p. 359, while the results of his experiments on the electric fusion of metallic wires and the oxidation of metals, as well as those made upon the electricity of sifted powders and also in order to ascertain the effects of electricity upon gases, are to be found recorded at pp. 564, 592, 593 and 597, Vol. VIII of the 1855 “Britannica,” and at p. 46 (“Electricity”) of “Library of Useful Knowledge.”

References.—pp. 15, 16 of the last-named work; Poggendorff, Vol. II. pp. 938, 939; Figuier, “Exp. et Hist.,” 1857, Vol. IV. p. 267; Sturgeon’s “Lectures,” 1842, p. 11; Phil. Mag., Vols. XXXVII. p. 80; XLII. pp. 36, 261; XLIII. p. 20; XLVI. pp. 161, 259; likewise Ch. Samuel Weiss, at Poggendorff, Vol. II. pp. 1287–1289; “Bibl. Britan.,” Vol. XLIII, 1810, p. 166; Vol. XLVII, 1811, pp. 3, 113, 213, 313; Vol. LVI, 1814, pp. 197, 318.

A.D. 1814–1815.—Fraunhofer—Frauenhofer (Joseph von), a practical Bavarian physicist and optician, who had been assistant to the celebrated George Reichenbach, publishes his observations on spectra in a pamphlet entitled “Bestimmung des Brechungs und Farbenzerstreuungs-Vermögens ...”

In the latter work will be found detailed his experiments with the electric spark, which he found to give a different spectrum from all other lights. Sir David Brewster says that in order to obtain a continuous line of electrical light Fraunhofer brought to within half an inch of each other two conductors, and united them by a very fine glass thread. One of the conductors was connected with an electrical machine and the other communicated with the ground. In this manner the light appeared to pass continuously along the fibre of glass, which consequently formed a fine and brilliant line of light. When this luminous line was expanded by refraction, Fraunhofer saw that, in relation to the lines of its spectrum, electric light was very different both from the light of the sun and from that of a lamp. In this spectrum he met with several lines partly very clear, and one of which, in the green space, seemed very brilliant compared with other parts of the spectrum (Edin. Jour. of Sci., No. XV. p. 7). He saw in the orange another line not quite so bright, which appeared to be of the same colour as that in lamplight spectra; but in measuring its angle of refraction he found that its light was much more strongly refracted, and nearly as much as the yellow rays of lamplight. In the red rays toward the extremity of the spectrum, he observed a line of very little brightness, and yet its light had the same degree of refrangibility as the clear line of lamplight, while in the rest of the spectrum he saw the other four lines sufficiently bright. In a subsequent paper read at Munich in 1823 (“Neue Modifikation des Lichtes ...” or “New Modification of Light”) and in Schumacher’s “Astronomische Abhandlungen,” Fraunhofer states that, by means of the large electrical machine in the cabinet of the Academy of Munich, he obtained a spectrum of electric light in which he recognized a great number of light lines, and that he had determined the relative place of the lightest lines as well as the ratios of their intensities.

The introduction of the electric spark for the purpose of volatilizing metals was an important step in the development of spectral analysis, but although used by both Wollaston and Fraunhofer its true value in that particular line was not realized for many years after their time.

Fraunhofer is not only celebrated as one of the founders of spectrum analysis, but he is well known also as the inventor of many important philosophical instruments, being the constructor of the great Dorpat parallactic telescope, called by Struve the giant refractor. It was during the year 1814 that he measured and described the innumerable dark lines of the solar spectrum known as Fraunhofer’s lines, which were first noticed by Wollaston and reported upon by the latter to the Royal Society in 1802.

References.—M. Merz, “Das Leben und Wirken Fraunhofers,” Landshut, 1865; Ninth “Encycl. Brit.,” Vol. IX. p. 727; “Abh. der K. Bayer, Akad. d. Wiss.” for 1814 and 1815; Fraunhofer’s biography in the “Memoirs of the Astronomical Society of London,” Vol. III. p. 117; his “Determination ...” München, 1819; Whewell, “Hist. of Ind. Sci.,” 1859, Vol. II. p. 475; Sci. Am., Nov. 19, 1887, p. 321; Phil. Trans. for 1814, pp. 204, 205, and for 1820, p. 95; Tyndall, “Heat as a Mode of Motion,” 1873, pp. 485, 486; article “Optics” in eighth “Encycl. Brit.,” Vol. XVI. pp. 544, 588, 591; Sir David Brewster’s article on “Electricity” in the “Encycl. Brit.”; “Mem. of the Roy. Bav. Acad. of Sci.” for 1822; “On the Spectrum of the Electric Arc,” in Jas. Dredge’s “Elec. Illum.,” Vol. I. pp. 32, 36; Edin. Trans., Vol. VIII for 1822; Edin. Jour. Sci., Vol. XIII. pp. 101, 251; Biblioth. Univ., Vol. VI. p. 21, as per Becquerel’s “Traité ...” Vol. I. p. 23; Dr. William A. Miller’s first and third lectures before the Royal Institution in 1867; Houzeau et Lancaster, “Bibl. Gén.,” Vol. II. p. 136; Rich. A. Proctor, “Old and New Astronomy,” 1892, p. 787.

A.D. 1815.—Bohnenberger (Johann Joseph Friedrich von), 1765–1831, Professor of Mathematics and of Astronomy at the Tübingen University, constructs an extremely sensitive electrometer by suspending a single strip of gold leaf upon a wire midway between, though apart from, the insulated terminating discs of De Luc’s column.

With this contrivance he found that, however slightly the leaf was electrified, it was drawn to one of the poles according to the nature of the electricity affecting it, and he was thus enabled to observe not only the presence of the slightest electrical influence, but the kind of electricity which was present.

Noad gives, at p. 30 of his “Manual,” an illustration of the electrometer as subsequently improved by Becquerel, and states that Mr. Sturgeon describes (“Lectures on Galvanism,” 1843) a somewhat similar arrangement, the delicacy of which he states to be such that the cap (plate) being of zinc and of the size of a sixpence, the pendant leaf is caused to lean toward the negative pole by merely pressing a plate of copper, also the size of a sixpence, upon it, and when the copper is suddenly lifted up the leaf strikes. The different electrical states of the inside and outside of various articles of clothing were readily ascertained by this delicate electroscope.

M. Gottlieb Christian Bohnenberger, of Neuenberg (1732–1807), is the author of several works treating particularly of the electrical machine, the electric spark, the electric doubler, etc., published at Stuttgart between 1784 and 1798.

References.—“La Grande Encyclopédie,” Vol. VII. p. 84; L. W. Gilbert, Annalen der Physik, Vols. XXIII (for Behrend’s); XLIX, LI (for “Beschreibung ... empfindlichen elektrometers ...”); Annales de Chimie et de Physique, Vol. XVI. p. 91; J. C. Poggendorff, “Biogr.-Liter. Handwörterbuch ...” Vol. I. p. 226; Sci. Am. Supp., No. 519, p. 8290, for Pouillet’s remarks upon the effectiveness of dry pile electroscopes; De la Rive, “Treatise on Electricity,” Vol. I. pp. 54–56.

A.D. 1815.—Mr. B. M. Forster sends to the Philosophical Magazine (Vol. XLVII. pp. 344–345) the description of an electrical instrument called “The Thunderstorm Alarum,” which can be made to show the effect produced by the passage of a charged cloud over an atmospherical electrometer.

He had several years before described, at p. 205 of the same publication, a method of fitting up in portable form one of De Luc’s electrical columns, respecting which latter he subsequently addressed communications, which appeared in Vols. XXXV. pp. 317, 399, 468; XXXVI. pp. 74, 317, 472; XXXVII. pp. 197, 265, also relative to one which he constructed and which ran continuously for five months.

References.—Phil. Mag., Vol. IV for 1828, p. 463; eighth “Britannica,” Vol. XXI. p. 619.

A.D. 1815.—Gregory (Olinthus Gilbert), LL.D., Professor of Mathematics at the Royal Military Academy, Woolwich, in his “Treatise on Mechanics,” London, 1815 (Vol. II. pp. 442–449), describes the methods of transmitting distant signals introduced by Polybius, the Marquis of Worcester, Robert Hooke, Amontons and Chappe, and alludes to an improved telegraph described in the “Gentleman’s Magazine,” as well as to the so-called nocturnal telegraph, of which an account is to be found in the Repertory of the Arts and Manufactures (“Biographie Générale,” Tome XXI. p. 903).