274 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



ten iiiilef< in length and a mile and three quarters broad at its termination, 

 the lower portion, for a distance of three miles, being covered with morainic 

 detritus.* The climatic conditions of the region where these glaciei's occur 

 Avill easily be understood when we call to mind its peculiar position with 

 reference to the prevailing westerly winds blowing across the warm South 

 Indian Ocean.f The amount of erosion caused by the abundant precipita- 

 tion, as described by Haast, is indeed remarkable. Mountains of from 5,000 

 to 6,000 feet in elevation have piled up against their flanks masses of gravel 

 thousands of feet in thickness, the terraced character of which indicates — 

 to the present writer, at least — most clearly the gradual diminution of the 

 amount of precipitation in later geological times. We have in these detrital 

 masses of New Zealand the exact parallel of the •' washes " of the Great 

 Basin Region.^ 



The Asiatic continent may well be considered as likely to throw light on 

 all points connected with either present or past glaciation. Having an area 

 greater than that of North and South America combined by nearly two and a 

 half million square miles, being in foct much the largest land mass of the globe, 

 — Europe proper seeming but a mere diminutive appendage to it, — we natu- 

 rally turn thither with the expectation of flnding illustrations of every kind of 

 climatic condition possible under present circumstances. This vast mass of 

 land extends from the equator to beyond the 75th parallel of latitude, and 

 embraces every variety of surface, including the most complicated mountain 

 systems, the highest summits, the most elevated and extensive table-lands 

 and the grandest plains of the globe. Its lofty chains are developed in 

 almost unbroken sequence from the Tropics to the Arctic Circle. It would 

 seem, therefore, impossible that any phenomenon affecting the earth in 

 general should not have manifested itself over some part of this continental 

 mass. Hence, if we seek to determine whether there has once been a Polar 

 ice-cap covering a portion of the northern hemisphere, or a period of general 

 glaciation not proceeding from the Polar regions, or, in fact, any great 

 change, or series of changes, in the climatic conditions of the earth from 

 epoch to epoch, it is to Asia that -we seem to be most fully authorized to 

 turn for evidence bearing on the question brought up for investigation, and 



* See Nni-Seeland, by F. von Hochstetter, Stuttgart, 1863, p. 348. 



t Mr. I. C. Kussell, in the Annals of the N. Y. Lyceum of Natural History, Vol. XI. p. 252, gives the rain- 

 fall at Hokitika, on the West Coast, from May to Derpmber, 18.56, at 96.082 inches; at Christchurch, on the 

 eastern side of the mountains, during the same period, it was only 17.395 inches. 



t See ini/c, jx 36. 



