House of Commons Papers Volume 1878: V.52

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1878 Excerpt: ...by it. The opportunities for observing the spectrum of the aurora in this position have been most unsatisfactory, as the displays were small in number and deficient in brilliancy. The form they generally assumed was to rise like an arch from a portion of the horizon where there was a luminous glow, at first very faint, but gradually increasing in brilliancy till near the zenith, where it would remain stationary for a short time and then bieak up and disappear. Sometimes they would rise up as streamers, but only occasionally was more than one visible at a time, and they lasted for such a short time, that even if they had been bright it would have been very difficult to make satisfactory observations. Very few showed any signs of colour, and those only the slightest tinge. Nearly all that were observed gave the citron line with the small pocket spectroscope with more or less distinctness, though no signs of any other lines were ever seen; but on only two occasions was it bright enough to get the line with Nury's spectroscope, and then only for such a short time that a satisfactory measure could not be obtained. Solar spectrum.--No observations of the solar spectrum were obtained, as in the autumn the sun was obscured by cloud or fog nearly the whole time, so that the only opportunities which my other duties allowed me to avail myself of were occupied in trying to adjust the large spectroscope which was out of order, and in which I was not successful before the sun disappeared altogether before the horizon. During the winter I got it nearly into working order, but since the sun has returned this spring the temperature has been so low as to prevent any observations being made, and the start of the sledges as soon as there is a rise precludes any chance this sea...