208 Physical Geography of 



experienced in reacting the glacier. Another tributary which, two 

 miles above its junction, divides into two branches, both issuing from 

 glaciers, reaches the Stewart four miles below its sources. The latter, 

 after a course of six miles, enters the main valley where, at the junction 

 of the Park stream, the third glacier branch, it opens up considerably. 

 Erom here the Wilberforce flows for thirteen miles in a south-south- 

 east direction, having a broad shingle bed which, however, is some- 

 times narrowed considerably by old morainic accumulations crossing 

 it. At the same time it also presents features similar to the valley of 

 the Bakaia. Two roclies moutonnees stand here also in the centre of 

 the valley, Groat Hill on the right, and Scott Hill on the left, the river 

 flowing between them. Both are joined to the high ranges forming the 

 valley, by a succession of shingle-fans, often very large. These low hills 

 are also very much ice-worn, and have sloping shelves on their sides 

 on which, and on the summit, are perched erratic blocks, derived from 

 the central chain. Goat Hill lies about 150 feet above the river, and 

 is half a mile broad and two miles long, gradually narrowing and dis- 

 appearing towards north under the fan of Boulder-stream gully, which 

 is of considerable dimensions. Below Goat Hill, the "Wilberforce 

 turns sharply to the south-west, being here joined by the River 

 Harper, the main branch of which, the Avoca, has its sources on the 

 southern slopes of Mount Greenlaw, and which after a course of 

 thirteen miles, joins the Harper six miles above its junction with the 

 "Wilberforce. The Avoca, of which I described the principal features 

 in the first part, has a gorge-like character after leaving the slopes of 

 the Southern Alps, but for the last eight miles of its course, the valley 

 widens considerably, and has grassy terraces on both sides. The 

 Harper, the sources of which are situated on the southern slopes o£ 

 the Black and Cragieburn ranges, flows for about eight miles in 

 a narrow and nearly straight valley to its junction with the Avoca, 

 after which its name is retained to its junction with the Wilber- 

 force. Another tributary, the outlet of Lake Coleridge, after a short 

 north-westerly course of about one mile, joins the "Wilberforce at this 

 turn, which now flows for three miles south-west, and then altering its 

 course for five miles to the south-east, joins the main valley of the 

 Rakaia. However, before proceeding to follow the downward course 

 of the united Rakaia, I wish to make a few observations on Lake 

 Coleridge and its principal tributary, the Eyton. Lake Coleridge is 

 eleven miles long, and on the average one mile and a half broad ; it 

 forms the continuation of the valley of the Wilberforce from which it is 



