References.—The obituary notice contributed by Dr. J. H. Gladstone to the proceedings of the Royal Society; Chemical News, Amer. reprint, Vol. II. pp. 198, 233; also p. 293 for accounts given by Sir J. Simpson and Prof. Fraser; J. Robison and Brewster, “A System of Mechan. Phil.,” London and Edin., 1822; Ferguson and Brewster’s “Essays and Treatises on Astr. Elect.,” etc., Edinburgh, 1823; Brewster’s several articles in the “Encycl. Britannica,” 7th and 8th editions, on “Electricity and Magnetism”; Transactions of the Roy. Soc. of Edinburgh, Vols. IX. 1821; XX. Part IV; Edin. Jour. of Sci., Oct. 1824, No. 2, p. 213; Noad, “Manual,” London, 1859, pp. 31, 32, 636–638; Harris, “Magnetism,” Part III. p. 119; Whewell, “Hist. of Induc. Sci.,” 1859, Vol. II. pp. 75, 81, 331, 332; the lectures delivered by Wm. A. Miller during 1867 before the Royal Institution of Great Britain.
Charles Babbage (1792–1871), a prominent English scientist who is mentioned above and who besides being one of the founders of the Royal Astronomical Society, as has already been stated, was also a founder of the British Association and the originator of the Statistical Society, is the author of valuable papers, exhibiting a wide range of learning and research—mainly on mathematical subjects and relating to magnetical and electrical phenomena—which have been published in the Reports of the Royal and other Societies (“English Cycl.,” Vol. I. p. 457; “Encyl. Brit.,” ninth ed., Vol. III. p. 178; Larousse, “Dict.,” Vol. II. pp. 5–6; account of Babbage’s work in C. R. Weld’s “Hist. Roy. Soc.,” Vol. II. pp. 369–391).
A.D. 1820.—Fisher (George) (1794–1873), who two years before had joined Captain David Buchan in his voyage to the Arctic regions, is the first to point out the true cause of the sudden alteration in the rates of chronometers at sea. “He observed,” says Dr. Roget, “that the chronometers on board the ‘Dorothea’ and ‘Trent’ had a different rate of going from that they had on shore, even when these vessels had been frozen in, and therefore when their motion could not have contributed to that variation; ... this effect could be attributed only to the magnetic action exerted by the iron in the ships upon the inner rim of the balance of the chronometers, which is made of steel. A similar influence was perceptible on placing magnets in the neighbourhood of the chronometers. This conclusion was confirmed by experiments made for this purpose by Mr. Barlow, who ascertained that masses of iron devoid of all permanent magnetism occasioned an alteration in the rates of chronometers placed in different positions in their vicinity.”
References.—Fisher’s article “On the Errors in Longitude as Determined by Chronometers at Sea, Arising from the Action of the Iron in the Ships upon the Chronometers,” communicated by John Barrow, F.R.S., to the Phil. Mag., Vol. LVII. pp. 249–257. See besides, Edinburgh Jour. Sci., London, 1826, Vol. V. p. 224; Phil. Trans. for 1820, Part. II. p. 196, and the volume for 1833, relative to magnetical experiments; also the “Lib. U. K.” (Magn.), p. 63. For Capt. Buchan, consult Barrow’s “Chronological History of Voyages into the Arctic Regions.”
Mr. George Thomas Fischer (1722–1848) is the author of “A Practical Treatise on Medical Electricity” (Poggendorff, Vol. I. p. 756).
A.D. 1820.—Bonnycastle (Charles), Professor of Mathematics in the University of Virginia, treats of the distribution of the magnetic fluids in masses of iron, as well as of the deviations which they produce in compasses placed within their influence, at pp. 446–456, Vol. LV of Tilloch’s Philosophical Magazine.
He refers to the then recent publication of Peter Barlow’s “Essay on Magnetic Attractions,” containing the results of many experiments, made principally upon spheres of iron, as well as to Dr. Young’s views of the subject, which were printed by order of the Board of Longitude, and he says that the principle upon which he intends establishing his inquiry “is an extension of the law that regulates the action of electrified bodies upon conductors; which was first given by M. Poisson in the Memoirs of the Institute for 1811, and employed by him to determine the development of the electric fluids in spheres that mutually act on each other.”
The afore-named dissertation, at the time, called forth a rejoinder from a correspondent and a further communication from Mr. Bonnycastle, both of which appear at pp. 346–350, Vol. LVI of the same publication.
References.—Silliman’s Journal, Vol. XL. p. 32; “Sketch of the Life of Chas. Bonnycastle,” by Thomas Thomson; Poggendorff, Vol. I. pp. 234, 235; article “Magnetism,” p. 9, Vol. XIV of the eighth “Britannica.”
A.D. 1820.—Harris (Wm. Snow), member of the College of Surgeons, and a very distinguished English scientist (1791–1867), proposes to the Board of the Admiralty his system of lightning conductors, of which an account appears at p. 231, Vol. LX of the Phil. Mag., as well as in a separate work published at London during 1822. This is followed by his “Observations on the Effects of Lightning ...” 1823, and by papers relative to the defence of ships and buildings from lightning, which were published, more particularly, in several numbers of the Nautical Magazine, the Phil. Mag., the Annals of Electricity, and in the Proc. Lond. Elec. Soc. for 1842, as well as in his “Record of Phil. Papers,” and under separate heads during many years between 1827 and 1854. One of his biographers remarks: