ATMOSPHERIC AND AQUATIC CHANGES IN AUCKLAND.

New Zealand Herald, Volume XV, Issue 5065, 9 February 1878, Page 6

ATMOSPHERIC AND AQUATIC CHANGES IN AUCKLAND.

The following Notes on the subject of the meteorology of Auckland and the alterations in. the harbour, observed within the past ten years, are taken from a recent report by Air. Burges3, the Harbourmaster : " With reference" to notable changes that have taken place in the weather at the port of Auckland, and the silting up of the harbour within the last thirty (30) years, 1 have to state that, as regards the weather, there is a marked change since I came hare, in September, IS4G; then, and for some fifteen years after, south-west and westerly winds prevailed for abuut nine mouths in the year—north east and easterly winds coming regularly about full and change of the moon, seldom lasting niorc thau forty-e:ght hours, and uEtsally ending ill a gale with heavy rain, shifting suddenly to north-west and south-west, but sometimes remaining at west for a week or more, blowing very hard with violent rain squalls. Daring the suirmer months land and sea breezes were pretty regular—i.e., north east in the day, \nd south-west at night. Of late years the finds have been more variable; south east nd north-easterly winds being mo«t prevr,ent, and heavy gales less frequent; south:ast gales being seldom felt far. up Hauraki Gulf—i.e., within a line from Cape Colville to the Kawan, although blowing at times with great violence outside this line. When a south-easter does reach Auckland it is generally accompanied with heavy rain. And here I may mention that rain' u less freqnent of late years, but, heavier for the time'when it dots come. In the earlier years mentioned, I have known it rain a continuous drizzle a week at a time. The cutting down of extensive forests that existed near Auckland some twenty-five years ago has no donbt had some effect in reducing the • rainfall here, as heavy rains are often reported as falling at Matakana, Omaha, and other thickly-wooded districts around us, when there is a. total absence of rain at Auckland. In fact, there is an evident change in the climate.

"As regards the silting up of the harbour, tho following extracts from a report of mine to tho Maruie Department, in June, IS6S, shows what was going on previous to that date " ' The harbour of Auckland is shoaling on its southern shore, as you will jferceive by the dotted (fed) lines on the chart,_ which is nearly diy at low water—spring tides—tbe tongue of Acheron Point having grown out rapidly within the last few yeirs ; but I do not notice any change in tho main channel or bed of the harbour. I think the Queenstreet Wharf and Breakwater running out laterally to the course of tlie tide inay account for the rising of the sand-banks above, for where it now dries at low water there was from four to five feet o£ water twenty years ago. '"The old stone pier off Point Britomart has been removed, and a new Breakwater runs out about 450 feet from the same paint, to a depth of-seven feet at low water. " ' Off St George's Bay I have marked the position of a patch of rocks with three feet water over them at low water spring tides. " ' The shore from Point Britomart to the Bastion is silting up a little. "' Off the North Head, and near the Rough Rock, a sand-bank has grown up very rapidly within the last few years, having but two (2) fathoms water on it at low water, the chart showing four and a quarter (4|) fathoms. " 4 The white buoy on the Sandspit, within the North Head, yon will see, has been shifted further out, consequent upon the extension of the spit.' " With referenco to the above remarks, I may mention that there is but three feet of water at the end of the Breakwater instead of seven, as reported in ISGS ; also that the rocks off St. George's Bay are evidently rising; and that the sand-bank near the Rough Rock is spreading, and if it continues to do so, will eventually meet the saudy tongue that is fast running out from the-north-eastern extreme of the North Head. "Tbe tail end of the Bandspit within the Nort'i Head is now shifting more inshore, consequent, I believe, upi>n the prevalence of easterly winds {before mentioned) and a stronger tide, caused by the reclamations on the south shore of the harbour. Tbe tide is also encroaching on the shore above the spit. "As regards the silting np of the south shore of the harbour, it was not perceptible until the carrying out of the harbour improvements or works, their irregular line of construction and obstructive nature to the natural course of the tide tending greatly to this increased silting np, i-e., these works, in obstructing the true course of the tide have caused eddy-tides, and a longer period of slack- water on this shore, thereby facilitating the deposit of silt, &c., that is carried into the harbour, from the drainage and sweepings of the city and suburbs of Auckland, and the shores of the harbour above. Moreover, when a large number of vessels occupy the wharves at one time, and many of them ground there, the silting is still further increased, as explained in tho following extract from my letter of 10th February, 187 li: —'Again, when large and heavydraught vessels arc alongside the wharf and take the ground, they siuk into the mud, and throw up a bank around them, particularly about the bilges; with a paucity of shipping for any length of time, and spring tides, these banks partially subside, but there can be no doubt that, were a large number of vessels continually occupying the wharf, the depth of water, from tbe cause mentioned, would gradually decrease. I may also mention that the mail boats, when they arrive, generally draw from 22 to 23 feet of water.'

"Adverting to my letter of the 30th of October last, respecting the grounding of the mail steamer City of New York alongside the Queen-street Wharf, I have farther to report that the City of Sydney, when here lately, bad to leave the wharf two hoars before her advertised time (otherwise she would have had to remain aground about four hoars, or two hoars after her proper time for leaving), and unless dredging operations are to be carried out on a more extensive and comprehensive plan (as intimated in my report of theJ6U» July, 3877, respecting the present dredge. and future dredging operations).- shipping accommodation at the wharves will eventually be limited to vessels of a light draught of water, as masters of vessels, aa a rale, have a decided objection (and.very .properly so) to let their vessels ground." " L J. Bubqkss. "3rd January,