56 
noted that the present entrance is but a little over a quarter of a 
mile wide, while the more southerly of the two old channels was 
over a mile in width. 
If, as seems probable, the sea on the latest submergence 
stretched as a strait from King George’s Sound to Torbay Inlet 
w ith Darwin Ridge as an island, such strait ( W'hich might for con- 
venience he referred to as the “Grassmere Strait”) has since been 
largely silted up, and has now become tlie Grassmere Valley, with 
the lakes, such as Grassmere or Lake Powell and others, as tem- 
porary phases in the growth of the land. The conversion of w'ater 
into dry land has been considerably assisted in this area by the for- 
mation in the beds of fresh water lakes of thick deposits of diatom 
frustules. By this means Grassmere has been plainly reduced to 
one half its earlier extent, wdiat was formerly the southern half of 
the lake being now' occupied by a dry bed of diatomaceous earth at 
least six feet thick. 
None of the three channels forming the entrance to King 
George's Sound has yet been converted into dry land, but the 
Admiralty charts show that there is a shallowing of the channel 
( the North Channel) betw’een the mainland and Michaelmas Island, 
which if continued wall result in the tying of the island to the 
mainland. 
The mouths of Oyster and Princess Royal Harbours still 
remain open. In the former case, the flow of water from the 
King and Kalgan Rivers, together wdth the tide, may be responsible 
Tor this, but in the latter case, although the tide probaltly has some 
influence, dredging has to be continuously ])ractise(i to keep an open 
waterway of the necessary depth. 
One of the general results of the building of the sand bars is 
to facilitate silting and consequently to rapidly increase the area of 
land reclaimed from the sea. the materials forming the new land 
being the detritus brottght down by the rivers and creeks and the 
sands carried by tides, currents or wdnds into the silting area. As 
this silting up jirogrcsses, and assuming no deformation. Oyster 
Harbour, amongst other changes, will disappear, and its place will 
be taken by low swampy lan<], through wdiich the King and Kalgan 
Rivers will meander, but as one river, the two having become en- 
grafted by the reclamation of the land. 
Another result is the smoothing of the coast line which lies to 
the cast of Albany, where immediately following the latest submer- 
gence, the coast was more broken and irregular than the present 
one. 
By the process of natural reclamation here outlined, swampv 
land is formed, which on being drained, is well suited to the grow'th 
of various agricultural products. 
