XXIX 



Such speculations as to the mode in 

 which nature has thus formed a closed 

 lagoon out of a wide bay are not so fanci- 

 ful as some people might think ; hundreds 

 of lagoons in other countries are proved to 

 have been so formed ; but the most re- 

 markable instance I know of is to be seen 

 in New Zealand. On the west coast of the 

 South Island there is a constant drift of 

 the material of the beaches, whether 

 shingle or sand, towards the north, caused 

 by the oblique set of the prevailing S.W. 

 waves on the beach. At the west opening 

 of Cook's Strait this coastal drift is 

 deflected towards the east by the pre- 

 vailing S.A\., W,, and X.W. winds and 

 waves, and has formed the Farewell Spit, 

 a tongue of sand over 20 miles long, and 

 from two to five miles wide, which en- 

 closes Blind and Massacre bays. It has 

 been observed that this spit is extending 

 and deflecting towards the land, the only 

 source from Avhich it can grow being the 

 sand swept up the West Coast and washed 

 along the spit to its end, and in the course 

 of thousands of years it will entirely en- 

 close Massacre Bay, and make an immense 

 lagoon of it. 



Some thousands of years ago the bar and 

 the entrance of the harbour was many 

 miles inside of its present position, which 

 is shown by the extensive sand banks in- 

 side the entrance, but still more con- 

 vincingly by great beds of wind-drifted 

 sea sand which lie on the hill sides of 

 Cape Sorell peninsula, many miles inside 

 the present entrance, and facing the 

 shore of the harbour. The quartz hills of 

 the peninsula are covered with a more or 

 less thick bed of peat, wiiich adheres to 

 the smooth face of the quartzite, so that no 

 sea sand is found on that side excepc such 

 as has crossed the entrance from the 

 Strahan side. Under the conditions of 

 deep water and strong currents sand can 

 cross over only from the east to the west 

 side on the bar, where the waves and 

 the breakers drive it across. If, therefore, 

 thick beds of pure white sea sand are 

 found lying on the hill sides some miles 

 inside of the present bar, the inference is 

 that the bar was near them in those days, 

 and has been pushed out to its present 

 position by the drifting of the sand along 

 the northern beach. There is no other 

 source from which this action could arise, 

 because the sand brought down by the 

 Gordon, King, and numerous creeks stops 

 at their mouths, as it cannot cross the 

 deep water of the harbour, where there are 

 no currents on the bottom. 



The above conclusions would appear to 

 contradict what I said in my report to the 

 Government of December, 1897, viz., that 

 at appeared that if there were any coast 

 -drift on the sea beach it was to the north- 

 ward ; but there is no contradiction, De- 

 <;ause when there is a strong flood tide 



running into the harbour, the indraft is so 

 great that it causes a powerful eddy of the 

 sea water for nearly a mile and a half 

 along the north beach, where the sea water 

 is seen flowing along the beach into the 

 harbour, and, of course, carrying the sand 

 with it ; but beyond the mile and a half 

 the appearances are as if there was a drift 

 towards the north. 



This circulation of sand at the entrance 

 is very extraordinary, and several times I 

 looked with astonishment when a power- 

 ful flood tide was rushing into the harbour 

 to see the whole of the water yellow with 

 sand in such vast quantities that one was 

 inclined to fear that the whole harbour 

 would be presentl}' flUed up with it : but, 

 then, after some days, the water ebbed out 

 with even greater violence, and then the 

 stream of sand flowing out to sea oft" all 

 the sandbanks for miles up the harbour 

 was equally astonishing. It would appear 

 quite likely that the great sandbanks 

 which obstruct the entrance are slowly 

 growing, because one argues that the 

 rough waves on the bar stir up the sand, 

 which the flood tides carry into the har- 

 bour, where, meeting still water the sand 

 settles to the bottom, and thus causes the 

 slow growth of the sandbanks inside ; 

 also the sudden drop of the shallow water 

 into 50ft. and 60ft. depths inside the lagoon 

 generally indicates either growth or 

 movement of the banks by scours. But, 

 however this may be, a close inspection of 

 the old chart of 1S19 does not disclose any 

 change in position or depths of the sand- 

 banks nor in the position or depth of the 

 sea bar. 



The water of Macquarie Harbour is salt, 

 but the colour of it is dark brown, caused 

 by the peaty water brought down by the 

 rivers ; this water stains the rocks black, 

 and even in the open sea at Pilot Bay the 

 rocks are so stained, except when a heavy 

 gale scours them white again. This l)rown 

 water is evidently distasteful to fish, as 

 there is not nearly so many in the harbour 

 as one would expect ; but Mr. Alexander 

 Morton has a salmon trout which was 

 caught near Strahan, and if these become 

 plentiful it will be a great improvement to 

 the harbour. 



A striking peculiarity is the erratic and 

 peculiar char-icter of the tides. There is 

 only one tide in 24 hours, and the average 

 height at the Heads is 2ft. Gin., but this 

 varies so much with wind and weather, 

 that it is impossible to predict the tides. 

 Very often the tide is seen to be what 

 sailors call bulling, that is, the tide falls 

 for an hour or two, and then rises again to 

 near its first height, and finally falls to low 

 water. For half of the year high water is 

 at night, and for the other half in 

 the day time. Sometimes for days there 

 is scarcely any tide, and the^ water 

 does not run in or oat, then without 



