XxXxiv. ABSTRACT OF PROCEEDINGS. 
not affect the elongation or contraction of area in any regular 
manner : and at any one temperature the variation in these two 
quantities is so variable for different specimens that no particular 
percentage could be included in a specification for the supply of 
copper. (c) The elastic limit in tension occurs at about 5,400 bbs. 
per square inch: this limit probably decreases rapidly with 
increase of temperature, but the differences in the behaviour of 
individual specimens are so great as to prevent the determination 
of the relationship between the two quantities. (d) The elastic 
limit in compression occurs at about 3,200 Ibs. per square inch: it 
decreases with increase of temperature, the relationship between 
the two being more regular than in the tensile tests. (¢) The 
rate of permanent extension and compression increases rapidly 
with increase of temperature. 
2. “ Aurora Australis,” by H. C. RussE.t, B.A., C.M.G., F-R.S. 
This paper contained a list of auroral displays in the southern 
hemisphere during 1897, also a detailed account of one which was 
observed by the captain and officers of the R.M.S. “ Aorangi,” on 
April 20th, 1897, when the ship was in Long. 96° W. and Lat. 
473° 8, It was first seen as a diffused white glow over the 
southern horizon at 6°30 p.m.; shortly after this, white rays shot 
out from the white glow in all directions, many of them along the 
eastern horizon, and it was observed that these rays rose above 
the horizon and drifted across the sky to the west. Closer inspec 
tion revealed the fact, that every ray and patch of light, including 
the zenith ring that was seen later was drifting to the west. 
Every part of the auroral light, rays and patches was white up 
to 8°30 p.m., then suddenly the white gave way to colours, and 
every ray and fragment of light was tinted with brilliant shades 
of red, green, and yellow. Then an arch appeared above the 
southern horizon, brilliant with yellow and green in its central 
parts and roseate hues near the horizon. As this arch rose higher 
another followed it until at last six of these beautifully coloured 
arches spanned the sky from the southern horizon to within 60° 
