References.—W. L. Krafft, “Observation,” etc., in Acta Acad. Petropol. for 1778, Part I. Hist., p. 45; Phil. Trans., XLI. pp. 840, 843; XLVI. pp. 319, 345; Chr. Hansteen, “On the Polar Lights,” London, 1827.

Zodiacal Light

This phenomenon, from its occasional faint resemblance to and association with the auroras, would seem to deserve mention here, though none of the conjectures formed, more particularly by Cassini, Euler, Mairan, Kepler, Laplace, Fatio de Duiller, Schubert, Poisson, Olmsted, Biot, Herschel, Delambre, Olbers or Sir Wm. Thomson attribute to it any electric or magnetic origin.

In the Report of the Proceedings of the Reale Istituto Lombardo, 1876, however, appears the account of many observations confirmed by M. Serpieri which “demand absolutely” the conclusion that the zodiacal light “is an electrical aurora preceding and following the sun round the earth.”

Angstrom asserted that he observed the auroral line in the spectrum of the zodiacal light, and Lewis saw the latter during the aurora of May 2, 1877. Humboldt, who observed it (“Cosmos,” 1849, Vol. I. p. 126) in the Andes at an elevation of 13,000 to 15,000 feet, as well as on “the boundless grassy plains, the Llanos of Venezuela, and on the seashore, beneath the ever-clear sky of Cumana,” believes it to be caused by “a very compressed annulus of nebulous matter, revolving freely in space between the orbits of Venus and Mars.” In this connection he refers to Arago in the Annuaire for 1832, p. 246, and to a letter published in Comptes Rendus, XVI, 1843, p. 687, from which the following is extracted: “Several physical facts appear to indicate that, in a mechanical separation of matter into its smallest particles, if the mass be very small in relation to the surface, the electrical tension may increase sufficiently for the production of light and heat.”

In Chambers’ “Descript. Astronomy,” p. 257, the historian Nicephorus is credited with first calling attention to the existence of this phenomenon, to which Giovanni Domenico Cassini gave the name of Zodiacal Light, after determining its relations in space during the year 1683 (Mém. de l’Académie, 1730, Tome VIII. pp. 188 and 276), but to Childrey belongs the credit of having given to Europe the first explicit description of this phenomenon at p. 183 of his 1661 “Britannia Baconica.”

References.—Sturgeon’s Annals, etc., Vol. II. pp. 140–142; Prof. C. W. Prichett’s paper in Sci. Am. Supp., No. 126, p. 2008, and the conclusions reached by Herr Gronemann (Archives Néerlandaises) in Sci. Am. Supp., No. 327, p. 5221; Whewell, “Hist. of the Ind. Sciences,” 1859, Vol. I. p. 531, and Vol. II. p. 609; Tyndall, “Heat as a Mode of Motion,” 1873, pp. 57, 58, 497, 498; J. F. J. Schmidt, “Das Zodiacallicht,” Braunschweig, 1856; the very interesting abstract given in “The Journal of the Brit. Assoc.,” Vol. XII. No. 5, of paper read by Rev. J. T. W. Claridge, F.R.S., Jan. 9, 1902; Houzeau et Lancaster, “Bibl. Générale,” Vol. II. 1882, pp. 763–771; “Pr. Roy. Soc. of Edin.,” XX. pt. 3; C. Wilkes, “Theory of Zod. Light,” Philad., 1857; Phil. Trans., Vol. XXXVIII. p. 249; “Cosmos,” 1849, Vol. I. pp. 126–134; “Anc. Mém. de Paris,” I, VIII and X; J. J. de Mairan, Paris, 1733; “U. S. Japan Expedition,” Vol. III, Washington, 1856.

A.D. 1684.—Hooke (Dr. Robert), English natural philosopher (1635–1703), who, in 1677, had succeeded Oldenburg as Secretary to the Royal Society, gives the earliest well-defined plan of telegraphic transmission, in a paper addressed to the Royal Society “showing a way how to communicate one’s mind at great distances ... 40, 100, 120, etc., miles ... in as short a time almost as a man could write what he would have sent.” His apparatus consisted of an elevated framework supporting an open screen, behind which were suspended as many wooden devices, or symbols, such as circles, squares, triangles, etc., as there were letters in the alphabet. In the daytime these devices were drawn up by a rope behind the screen and made visible in the open space, while during the night use was made of torches, lanterns or lights.

Hooke also showed, in 1684, that iron and steel rods can be permanently magnetized by strongly heating them and by rapidly cooling them in the magnetic meridian (“Enc. Brit.” 1857, Vol. XIV. p. 3).

But, what is still more singular, he had, even previous to the above-named date (i. e. in 1667), alluded to the possibility of telephoning, that is, communicating sound through a wire. He thus expresses himself: “And as glasses have highly promoted our seeing, so it is not improbable that there may be found many mechanical inventions to improve our other senses—of hearing, smelling, tasting, touching.... ’Tis not impossible to hear a whisper a furlong’s distance, it having been already done; and perhaps the nature of the thing would not make it more impossible though that furlong should be ten times multiplied. And though some famous authors have affirmed it impossible to hear through the thinnest plates of Muscovy glass, I know a way by which it is easy to hear one speak through a wall a yard thick. It has not been examined how far acoustics may be improved, nor what other ways there may be of quickening our hearing, or conveying sound through other bodies than the air, for that is not the only medium. I can assure the reader that I have, by the help of a distended wire, propagated the sound to a very considerable distance in an instant, or with as seemingly quick a motion as that of light, at least, incomparably swifter than that which at the same time was propagated through the air; and this not only in a straight line, or direct, but in one bended in many angles.”