114 The Past and Present of the Port of Melbourne, 



Forth, which was of open timber work, and was sufficient 

 obstruction to the passage of waves, that I have seen the 

 outside surface a mass of white water, whilst inside it 

 was comparatively smooth, and this at a time when, owing 

 to the fury of the gale blowing, the spray was breaking 

 nearly over the Bass Rock. This last case is an illustration 

 of the influence of open piling in checking wave action, 

 and if wave action, also currents. 



The above are given only as examples of cases which exist 

 in abundance, proving that currents are checked by open 

 timber piers, as well as by stone walls, and that both theory 

 and practice show that when such check takes place, matter 

 held in mechanical suspension must precipitate. 



Now if we examine what has taken place on the Williams- 

 town shore and in Hobson's Bay since 1853, we find precisely 

 the results which theory and practice point to as a probable 

 consequence of what has been done there, namely, a rapid 

 filling up in Hobson's Bay and heavy deposits of mud on the 

 Williamstown shore, owing to the stone walls and timber 

 piers having diverted the river currents, whereas the shore 

 used to have a clean surface of rock and kelp before the 

 construction of the works named. 



It is no unusual thing now, for one of our Colonial 

 steamers in passing Williamstown, to leave behind her a trail 

 of putrid mud, and it is only a few days ago a paragraph 

 appeared in the daily journals to the effect that mud had 

 deposited so thick at the steamboat jetty as to render it 

 inconvenient for use by the boats of light draft plying at 

 the pier, which is a state of things I imagine few will 

 regard as an improvement on the waters of 1853. 



In time of freshets, the river bringing down waters heavily 

 surcharged with mud, the brown water can be seen as 

 diverted by the stone walls right across the bay to Sand- 

 ridge, whilst the waters south of Point Gellibrand are 

 comparatively translucent. After heavy westerly weather, 

 when the waters of the bay rise above the stone dykes, the 

 brown water may be seen driven over into the Williamstown 

 recesses, but with little or no current, and it is indicative of 

 the extensive character of the mischief being done. The 

 actual extent of the evil is only realised by reference to 

 the soundings by Captain Cox, and more recently by 

 Commander Stanley. 



It has been suggested to me that the shoaling of the bay 

 waters may be accounted for by upheaval ; but I do not 



