



4 INTRODUCTION. 



mass of sea ice the extent of wbicb is not known, but wbich in all probability extends in 

 a north-nortb-westerly direction from Kin;^ Edward VII Land. A certain amount of detached 

 ice floats on the open sea and this is most abundant in the cast and in a l)c!t across tli 

 entrance to the sea in approximately latitude G7° S. In March new ice commences to form 

 and by the end of the month the ice is permanently fixed in sheltered bays and during 

 April and May this fiinge of ice extends outwards from the coast. During the winter the 

 cast of the sea and a belt along the coast of South Victoria Land are permanently frozen over, 

 between these two regions of fixed ice there is an area extending from the Barrier north- 

 wards to the open ocean some hundred miles cr so north of Cape Adare in which the sea 

 is sometimes frozen over and sometimes cleared of ice by the wind and in which the ice 

 never attains any great thickness. 



The Barrier. — It has been stated that Ross gave the name ' Bairier ' to the ice-cliif 

 which ban-ed his way to the south. Ross was not able to mount to the top of the cliff, 

 but when subsequent explorers did so they found it to be the seaward edge of a great 

 almost level plain of ice and snow. The name originally given by Ross to the cliff has 

 been extended to this great snow plain, and now the original significance has been lost and 

 the word ' Barrier ' is used almost exclusively as a place name for the level low-lying area 

 of snow and ice which is terminated on the north by the ice-cliff to which Ross gave the 

 name originally. 



On the west the Barrier is bounded by a continuation f)f th(^ escarpment which further 

 north has formed the western coast of the Ross Sea. Starting near Ross Island and pro- 

 ceeding due south along the level surface of the Barrier, one has on the right the lofty 

 mountains of the escarpment between which large glaciers flow down from the surface of 

 the plateau 8,000 to 10,000 feet above the level of the Banier. The high land continues 

 on the right until latitude 82° S. is reached, where the escarpment turns slowly to the 

 east and cuts across the direct way to the Pole. From 82° S., 160° E., the escarpment 

 of the plateau runs almost south-east to near 85° S., 160° W., where according to Amundsen's 

 observations it turns sharply to the right and continues in a more southerly direction, passing 

 within about 120 geographical miles of the Pole. 



The eastern boundary of the Barrier is unknown. There are indications of land in a 

 line to the south of King Edward VII Land, but it is almost certain that if land does 

 exist here it is low land or a series of low islands. For meteorological purposes we may 

 consider that the whole of the area beyond the escarpment of the plateau is low, and if 

 it is not actual Barrier it is snow-covered low land which is similar in most respects. 

 Neglecting for the present the character of the region to the east of longitude 160° W., we 

 may say that the area bounded on the north by the great ice-cliff joining Ross Island 

 and King Edward VII Land, on the west and south by the escarpment to the plateau and 

 on the east by longitude 160° W., is occupied by the Barrier. The area of this region is ap- 

 proximately 200,000 square miles, i.e., nearly the same as France. The distance from Ross Island 

 to the Beardmore (jlacier is almost exactly the same as from Paris to Marseilles. The whole 

 of this huge area is practically a level plain. Barometric determinations indicate that its 

 surface is on the average 170 feet above sea-level and this is only slightly higher than 

 the ice-clift"s on its northern edge. The question of the origin and the formation of the 

 Barrier is discussed elsewhere ; it is sufficient to give here the conclusions arrived at. There 

 is little doubt that for the greater part, if not for the whole, of its extent the Barrier is a 

 floating sheet of ice. If this is so and assuming that there is seven times as much ice below 

 the level of the sea as floats above, the average thickness of the sheet of ice is something 

 like 1,400 feet. The Barrier surface is snow, often soft, but sometimes hardened by the wind, 



