Auroræ: Their Characters and Spectra

The illustrations are mainly from original drawings of my own. Those from other sources are acknowledged. Messrs. Mintern have well reproduced in chromo-lithography the coloured...

In Seneca’s ‘Quæstiones Naturales,’ Lib. I. c. xiv., we find the following:—“Tempus est, alios quoque ignes percurrere, quorum diversæ figuræ sunt. Aliquando emicat stella, aliq...

“The flashes seem to be scattered beams approaching nearer to the earth, because they are similarly shaped and infinitely larger. I have called them flashes, because their appea...

Captain Sabine describes Auroræ seen at Melville Island (Parry’s first voyage, January 15). Towards the southern horizon an ordinary Aurora appeared. The luminous arch broke int...

Mr. G. Henry Kinahan writes to ‘Nature,’ from Ovoca, under date January 27th, 1877, and speaks of two distinct kinds of light so classed—one brilliant and transparent, of a whit...

In the Edinb. Encyc., Gmelin is stated, in continuation of his description of an Arctic Aurora, to add:—“For however fine the illumination may be, it is attended, as I have hear...

Dr. Richardson (‘Sir John Franklin’s Narrative’), so long ago as the years 1819-1822, made many recorded observations on the connexion of clouds with the Aurora Borealis in the...

In anticipation of the total eclipse of the Moon on the 27th February, 1877, several articles appeared in the leading journals of the day describing, for the public benefit, the...

Mr. Norman Lockyer, in his ‘Solar Physics,’ a work of 666 pages, gives but little space to the Aurora. The index comprises:—“Aurora Borealis, connexion with sun-spots, pp. 82-10...

At first the Aurora was described to be sulphurous vapours issuing from the earth; and Musschenbroek pointed out that certain chemical mixtures sent forth a phosphorescent vapou...

Any form of spectroscope of moderate dispersion will suffice for observations of the spectrum of the Aurora; but, for sake of convenience, a hand or direct-vision spectroscope i...

In order to test Professor Ångström’s theory of the Aurora, referred to in the last Chapter, in an experimental way, I examined, in the winter of 1874, some tube and other spect...

[The substance of these appeared in the ‘Philosophical Magazine’ for April 1875, in conjunction with the “Comparison of the Tube and other Spectra” (Chapter XI.), but they are n...

In a communication to ‘Nature,’ Mr. H. R. Procter has pointed out an apparent coincidence in position of several of the Auroral lines with those of a spectrum occasionally obtai...

The set of experiments detailed in Chapters XIV. to XIX. was mainly conducted for the purpose of testing, in connexion with the Aurora, the action of a magnet upon the electric...

(1) A small Geissler tube (No. 1) was lighted up by the small coil. The capillary part showed a very bright, slightly rosy-tinted stream. Negative bulb was filled with rosy-purp...

The capillary portion of a Geissler tube was cut away from the bulbs, cleaned, and connected by a small vulcanite tube with the gas-pipe in the room conveying coal-gas at ordina...

(1) To excite it the larger coil was used. The tube was filled with bright, steady, rosy light, and beautiful stratification, which, as it flickered, seemed to incline to a cont...

Mr. John Browning kindly lent me a large phosphorescent tube with five bulbs, said to be filled with anhydrous sulphurous-acid gas (SO₂). (See Plate XVIII. fig. 1.) This tube li...

It consisted centrally of a thin stream of bluish-white light, vividly bright, around which was seen a narrow, uniform, diffuse, yellow-tinted aura, which accompanied the spark...

(1) A globular receiver was used, having brass caps for exhaustion, and platinum wires passing through the opposite sides for electrodes (see Plate XVIII. fig. 6). With partial...

on stratification. In Plücker tube, action of magnet on negative pole (arc formed) and positive pole (Gassiot’s rings produced) demonstrated. Effects of magnet upon glow and spe...

demonstrated. Ångström’s flask experiment tested; same results not obtained unless one wire only was connected. Experiments demonstrating the action of a magnet on an electric s...

It is usual, in concluding a work on a special subject, to sum up its contents, and to examine the general results arrived at. This, however, it is not easy to do in the present...