470 
constructed for the purpose of developing the mines of chrome-ore 
on the Dun Mountain, and leads from the harbour through the 
town along the Brookstreet valley. 
The harbour of Nelson is safe, but small and difficult of access 
to larger sailing-vessels. It owes its formation to a most singular 
“boulder-bank” which extends eights miles along the coast, forming 
a natural dam, behind which there is a narrow and shallow arm 
of the sea, which grows deeper at its southern extremity, where 
it communicates with Blind Bay, and here forms the harbour. The 
Entrance to the Harbour of Kelson, 
with part of the Boulder bank. 
entrance to the harbour is between the southern extremity of the 
boulder-bank and the mainland, but is narrowed so much by the 
Arrow rock, 1 a rock rising in the middle of it, that the navigable 
channel is only 50 yards wide. Owing to the extremely swift cur- 
rent of the tide in this narrow channel and its shallowness, larger 
vessel can pass in and out only in time of high-water, and are 
moreover obliged to improve the tide in coming or going. These 
unfavorable circumstances would greatly disparage navigation , but 
for the excellent anchoring places outside the harbour, which by 
1 The Arrow rock consists of altered schists streaked with veins of quartz. 
It is covered all over with Mytilus and Balanus as far as highwater-mark. 
