E. Dozson.—State of Applied Science in Canterbury. 187 
The engineering works upon this line are of a very varied nature. In 
some places the cliffs are scarfed out for a portion of the width of the road, 
the remainder being carried on timber brackets, in the fashion of Trajan’s 
celebrated road on the bank of the Danube ; in others, the line is carried 
across ravines on embankments faced with walls made of timber cribbing, 
filled with blocks of stone. 
The fords in the rivers have been protected by wing dams formed of 
large trees backed with boulders; whilst in many places the mountain 
torrents have been made passable by building timber weirs across them, and 
filling up their beds to a uniform level with stones and gravel. Through 
the swampy forest the ground has been drained and fascined for many 
miles, whilst the whole length of the road has been thoroughly metalled. 
Amongst the bridges, that over the Taipo, 270 feet long, built upon piles, 
with steel shoes, driven into a mass of granite boulders, deserves mention 
as being a difficult work successfully executed, and which has, up to the 
present time, resisted the heaviest floods, although the stream has been at 
times blocked with drift timber from bank to bank. 
The explorations of Dr. Haast at the head-waters of the Molyneux, the 
Waitaki, the Rangitata, and the Rakaia, and those of the Provincial Engineer 
in the upper valley of the Waimakariri, have fully established the fact that 
throughout the entire length of the province there are only three real 
passes, viz., the Hurunui Saddle, dividing the sources of the Hurunui and 
Teremakau ; Haast’s Pass, at the head of Lake Wanaka, which leads over a 
very low saddle into the valley of the Haast River, which falls into the sea 
near Jackson Bay; and Arthur's Pass, which is nothing more than a great 
fissure, running in a tolerably direct line from the valley of the Waimakariri 
to that of the Teremakau. The so-called North Rakaia Pass has no real claim 
to the title, its eastern face being simply a wall rising abruptly from the valley 
to a height of 1,500 feet, and being quite impracticable for horses or cattle, 
besides being at so great an elevation as to be buried deep in snow during 
eight months in the year. An inspection of a good map of the province 
will help to explain this absence of passes throughout so great a distance. 
The rocks comprising the central chain have at a very early period been 
crumpled up into huge folds, the upper portions of which have been denuded, 
leaving the remaining portions of the strata standing up in vertical or highly 
inclined positions, the axis of the foldings having a tolerably uniform bearing 
of N.N.E. 
Now, it will be seen, on looking at the map, that the central chain ex- 
hibits two distinct systems of valleys, the one radiating from a common 
centre situated about fifty miles north of Mount Darwin, which includes 
all the rivers from the north to the south of the province, giving the idea 
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