MR BARR'S LECTURE-HARBOUR WORKS.

Otago Daily Times, Issue 6736, 17 September 1883, Page 3

MR BARR'S LECTURE-HARBOUR WORKS.

TO THE EDITOR.

Sir,—lt is full "12 months since I have troubled your columns or those of your contemporaries with any remarks of mino on the above sufcject. Sufficient public attention was arrested, and abler pens than mine were enlisted from the correspondence initiated at that period. I would not now venture to trespass on your space at this -timo had the engineer for the Harbour Board, in his jiaper before the Institute, not assumed the position of special pleader rather than tho recorder of facts, which past experience, and the tabulated records of reclamation and dredging, would have enabled him to do. There are many things omitted which I hope the new Board will fearlessly demand, and among such is: Tbe sum total of all the material dredged monthly during Proudfoot's contract and subsequently, with cost of same; or, what would be more businesslike, the total quantities dredged since the Harbour Board's lirst operations; then balance the sum total of this against the improvements saide to be achieved in the "Victoria Channel. The public has a right to be enlightened on this head, and it has been no fault of theirs that such information has not been supplied. I am much mistaken, if such are forthcoming, it ought, and, I believe, would show the re nioval of material sufficient to cut a channel from Dunedin to the Heads and miles beyond it, deep enough to admit tbe largest vessel afloat. - Mr Barr says in hia lecture, It is an axiom in marine engineering that it is dangerous to reduce the quantity of tidal water entering and leaving a harbour, as thereby the scouring effect at the entrance is reduced." And further on adds, "At the head of Dunedin Harbour somewhere about 200 acres have beeu reclaimed from first to last." Now why use an indefinate term as " somewhere " ? Why not givo the exact boundary-line where the reclamation stops the flow of tidal water to the Upper Harbour? The survey lines are doubtless well defined, and tho quantities as easily abstracted as quotations from works of modern engineers.

Mr Barr thinks tliat as a compensating setoff against the area reclaimed, the straightening of the Victoria Channel will form an equivalent. I doubt such being the case. If we take the area, aa Mr Barr says, as " soinowhere about 200 acres " (but which I believe is nearer 300), and tli" ay. ...g« depth of 6ft, the weight of each cubio fwt at 60 degrees mean temperature, say, (iliu, Uieu we have lor ono acre 16,727,0401b, or, for 200 acres 1,493,485 ona (ono million four hundred and ninetyhiee thousand four huudred and eighty-five o ns) '.

Will Mr Barr assert that such a volume of water can be compensated by the difference in tho depth of the Victoria Onannol, as it now exists, and what it waa in former yoars ? There is an axiom well known iii physical science—viz., whon two bodies meet of equal I weight and magnitude, they neutralise each other's force; where bodies of different weight and inagnitudo meet, tho lesser giveß way to the greator. AVill not the lessening the aroa within our harbour so contract the tidal- flow as to materially affect tho resistance of the never-ceasing battery of the Pacific at tlio Heads, unless the current there is contracted iv a corresponding ratio? I hope the now Harbour Board will direct their attontion to the bar—get our largest vessels inside, by all means. Ihis ought to bo a radical point which the outsido public should insist upon, and, as our means allow, bring them farther up tho bay. I confess having little_ confidence in tho Harbour Board. The training of the great majority has not boen of a character-to do much other than drop into the groove of . their predecessors; and although thoy are gentlemen oi high commercial integrity, and who would not stoop to anything shady, nevertheless I much doubt wnathor they ui'u tho best that could be found for the dischaigo of dutie9 which require years of study aud special training; and I hopo tho Oovernment, in their selection of gentlemen, will keep this object in view, and without which we may he classed iv the measure of intelligences with the Yorkshire farmer who, when Mr Mechi, of Tiptree Hall, was lecturing the farmers on the different kinds of soils suitable for different plants, and had ]'occasion to frequently mention mangold wurtzol—a name and a plant which was alike new to many of the audionce ;—ultimately, one of tho old aud orthodox farmers could bear tho name uo longer, and interrupted Mr Mechi, exclaiming, "Tha go whoam wi' the maugeral weired ! Ma faddor grew woats and beans; nn gionfaddoi- grow woats and beans; and ise inner grow nowfc but woats and beans." 1 sincerely hope the new Harbour Board will strike a new line of action, and aiui_ at something more iv accord with our requirements and advanced tone of thought, than persist in growing " woats and beans." —I am, ToiiMr Forthwith. ' September 15.