No. 2, a line very slightly more refrangible than F. The side towards D is sharp and well defined, while on the other side it is nebulous. No. 3, slightly less refrangible than G, is a broad ill-defined band, seen only with a wide slit. No. 4, a line near E, woolly at the edges, but rather sharp in the centre. This, says Lord Lindsay, should be at or near the position of the line 1474 of the solar corona. No. 5, a faint band, coincident with _b_, extending equally on both sides of it. The lines are numbered in order of intensity. It is questionable, from observations with instruments carrying a scale, whether the line-positions are exact; but the description of their characters is valuable. [Sidenote: Candle-spectrum.] As a candle blue-base spectrum is at times a ready and handy mode of reference in Auroral observations (as was found in this instance), I have, on Plate XI. fig. 5, given a representation of it as seen with my Auroral spectroscope. Dr. Watts’s corresponding carbon-spectrum is added on the lower margin. The numbers on the upper margin refer to my scale. [Illustration: Plate XI.] _Spectrum of the Aurora Australis._ [Sidenote: Captain Maclear’s spectra of Aurora Australis.] Captain Maclear, on examining the streamer seen by him Feb. 9th, 1874 (_antè_, p. 27), with the spectroscope, found three prominent lines in the yellow-green, green, and blue or purple, but not the red line. In the Aurora of March 3rd, 1874 (p. 27), he could trace four lines, three bright and one rather faint. They must have been exceedingly bright to show so plainly in full-moon light. [Sidenote: Instrument used, and mode of registering lines.] The spectroscope used was a Grubb single-prism with long collimator. A needle-point in the eyepiece marked the position of the lines; and a corresponding needle-point, carried on a frame by a screw movement in concord with the point of the eyepiece, scratched the lines on a plate of blackened glass. Two plates were taken. On the first were scratched the auroral lines and the solar lines as seen in the moonlight; on the second plate were scratched the auroral lines, the Solar lines from the moon, and the carbon lines in a spirit-lamp. [Sidenote: Copies of the two spectra obtained. Discrepancy in the spectra. Remarks on the spectra.]