406 Transactions. — Chemistry and Physics. 



time over the whole sky, their terminations being in the same 

 eastern and western portions of the horizon, and this simul- 

 taneously with a brilliant auroral light in the southern quarter. 

 The sky at the same time was free from clouds, and the air 

 calm. It is worthy of note that though on five out of six 

 times on which these bands have been observed the moon 

 was above the horizon, on this occasion it was invisible, as 

 it was new moon on the 23rd. This circumstance removes 

 some of the complexity which might otherwise arise in 

 accounting for this phenomenon, lunar halos of any descrip- 

 tion being inadmissible. 



A third display in the same year took place on the 13th 

 May, the arches extending* from east to west, a beautiful 

 lunar halo occurring at the same time, the moon being not 

 far from the northern quarter. The sky was slightly hazy, as 

 only large stars were seen, and the air was calm. 



Another display (and the earliest observed at this station) 

 took place on the 10th July, 1867, and in this case the bands, 

 instead of extending from east to west, stretched from uorth 

 to south, and it was compared at the time to the streamers of 

 an aurora australis meeting the streamers of aurora borealis. 

 An apt comparison, and one which would perhaps illustrate 

 the phenomenon more forcibly than a description, might be 

 made by supposing these bands as they appeared on this 

 occasion to represent a number of imaginary meridians at 

 some uniform distance above the globe. A very fine lunar 

 halo was seen at the same time, the moon being somewhat 

 west of the meridian ; the air was calm. Lunar halos were 

 also seen at Sydney on the 8th, 9th, and 10th. A similar 

 phenomenon occurred on the 29th March, 1869, in which the 

 bands extended from north to south, accompanied by a lunar 

 halo, the moon being near full and over the east. 



I shall instance another case by making the following 

 extracts from recorded meteorological observations. " On the 

 1st May, 1871, symmetrical bands of light seen at 9.45 p.m. 

 similar to those of 1870. They had their terminations east 

 and west ; were very distinct ; stars could be seen through 

 them. They radiated so regularly from the east and west 

 (fanlike) that a luminary might have been supposed to have 

 been under the hprizon at these points. On this occasion also 

 the moon was near the meridian and surrounded by a large 

 halo ; the air was calm." " A partial display occurred on the 

 25th September, 1871, in the eastern quarter, seen in broad 

 daylight, about 5.45 p.m. The radiations were straight, and 

 spread, fanlike, for about 35° upward from the horizon. The 

 edges of these bands were well defined, and not gradually 

 shaded off. They were unmistakably distinct from, and not 

 to be confounded with, light cirrus clouds which were also 



