14 



low ice crystals passing in low showers rapidly overhead with south-westerly wind. Sun visible 

 all the time : low fog-banks and drift all round horizon. Wind south-westerly. Temperature, +15 F. 



Plato IV. February 9, 1903. 5 J'.M. Mc.Murdo Sound. Drawn from a sketch by Lieutenant C. It. 

 KI.YPS, R.N. The prismatic halo round Sun is incomplete in this case, as is also the zenith-centred halo. 



Plate V. Solar phenomenon observed on February 12, 1903, in Mc.Murdo Sound. Drawn from a sketch 

 by Lieutenant C. R. ROYDS, R.N. No mock-sun was visible. Lower part of outer ring hidden by land. 

 A very faint white beam crossed the inner and outer ring. 



Plate VI. A fog bow frequently seen on the Great Ice Barrier when one stood, back to the Sun, in the 

 morning hours, shortly after midnight. It was always wliite, and brightest at the lower ends of the limbs. 

 A good example was observed on December 17, 1902, and another well-marked instance occurred on 

 November 15, 1902. 



Plate VII. A remarkable shadow which appeared constantly in the southern sky when the Sun was 

 below, or low down on, the northern horizon. It gave rise to many conjectures as to its cause, the most 

 probable being that it was the shadow of Mount Erebus and Mount Terror on a thin alto-stratus. Various 

 notes as to its appearance will be found in the Remarks of the Register, and also in the notes on clouds. 

 As the Sun moved apparently to the west, this shadow moved to the east, and was always visible in the 

 forenoons in clear weather, while the Sun was sufficiently low on the horizon. 



Plate VIII. A not uncommon type of cirrus cloud, or fracto-cirro-stratus, which often accompanied very 

 magnificent colour effects in spring and autumn when the Sun was low on the horizon for hours at a time. 



Plate IX. An unusual appearance at the summit of Mount Erebus, namely the differentiation of several 

 columns of steam issuing from distinct vents. This was possible only when there was a flat calm at 

 13,000 feet above sea level. The collection and condensation of the steam at a still higher level to form a 

 heavy cloud was less unusual. 



Plate X. represents the condensed vapour rising from the crater of Mount Erebus and acting as a wind 

 vane at a height of 13,000 feet above sea level. 



Plate XI. shows another phase in which the presence of a flat calm is demonstrated between about 

 13,000 feet and 14, 000 feet, while above this level the pennant of "smoke" clearly shows the presence 

 and direction of an upper current. 



Plate XII., fig. 1, from a photograph taken at Sea, March 2, 1904, looking to the north over an extent 

 of open ice-free water. The island, known as Buckle Island, is one of the Balleny group. Its summit is 

 hidden by the heavy stratus cloud which lies low over the water and forms a typical open-water sky, with 

 very little reflected light in it. 



Fig. 2, from a photograph taken in Wood Ray, February 21, 1904, looking westward to Mount 

 Melbourne. The cloud here represented, a fracto-cirro-stratus, is very much higher than that shown 

 in fig. 1, much higher even than the summit of Mount Melbourne, which is 8337 feet above sea level. 



Plate XIII., fig. 1, from a photograph taken in Robertson Bay, January 9, 1902, looking in a southerly 

 direction over a stretch of open water, above which hangs a typical low cumulo-stratus cloud. In the 

 distance are the ice-covered inland mountains of South Victoria Land, over which the sky is free from cloud. 



Fig. 2, from a photograph taken looking south-west from Cape Adare, February 24, 1904. In the 

 distance is a clear sky over the inland ice-covered mountains of South Victoria Land; the open water 

 of Robertson Bay, on the other hand, is overhung by a heavy stratus, whose edge coincides with the 

 coast line which lies beneath it. 



Plate XIV., fig. 1, from a photograph taken looking north, at Cape Adare, February 24, 1904. In the 

 far distance is seen the well-defined border of a low and extensive stratus overhanging the open sea. 



Fig. 2, from a photograph taken looking westward to Mount Melbourne. Small patches of cloud 

 which have formed at the summit of the higher peaks, from 8000 to 12,000 feet above sea level, are 

 seen to be floating off into an otherwise cloudless sky. Mount Melbourne is not known to have any 

 activity as a volcano, and the cloud patches must therefore be distinguished from such as are represented 

 in Plate IX. as forming round a nucleus of steam emitted from the active crater of Mount Erebus. 



