BIDWELL — HARBOUR WORKS. 
253 
utt enemy as well as from storms. These should be central for 
the defence of some important part of the coast and of the 
shipping frequenting it, and convenient for observing the move- 
ments of an enemy ; they should have a large area of anchoring 
ground with sufficient depth for warships of large draught ; and 
should be conveniently situated for the supply of coal, the con- 
centration of troops and stores, and so on. For Harbours of 
Kefuge for mercantile shipping or for fishing fleets the sites and 
designs must be determined by the probable local requirements, 
giving due regard to the factors of easiness of entrance and good 
sheltered anchorage at all states of the tide. 
As good examples of the “national” Harbour of Refuge, 
that which is now being constructed at Peterhead in Scotland, 
and that which is shortly to be commenced at Dover, may be 
cited. In the former case a bay, about a mile across, is being 
protected by two breakwaters running towards each other in a 
straight line, with an entrance 600 feet wide, having a depth of 
CO feet at Low Water spring tides. The area of this Harbour 
is 340 acres. At Dover an area of 685 acres is to be enclosed, 
by three breakwaters, the western arm being an extension of the 
existing Admiralty Pier ; there will be an entrance 800 feet wide 
between this and the South Breakwater, then another entrance 
000 feet wide, and then the eastern arm running in a straight 
line to the shore. Each entrance will have a depth of 42 feet 
at Low Water spring tides. There is also an inner pier in 
course of construction at present, enclosing an area of 75 acres 
between itself and the Admiralty Pier as a Commercial Harbour. 
(i) Peterhead. 
