RUBBISH AND SOOT

Evening Post, Volume CXXVIII, Issue 1, 1 July 1939, Page 10

RUBBISH AND SOOT

RESULT OF CALMS

HARBOUR DISFIGURED

From various complaints that ■ have been made recently, it seems as though the highj-windsand gales that are proverbial in Wellington are actually being- missed.' The harbour' is full of straw, bits of wood, bottles, and other floating rubbish that proceeds in stately fashion out and in with ' the tides without getting ashore, whereas when it blows, in the normal course, all. the flotsam becomes-jetsam becomingly, leaving the waters of the harbour clear.

! There is, perhaps more important, the fog that settles over the harbour and parts of the city.. Nobody likes to assume responsibility for the soot which hangs in the air when it does not blow in Wellington, but if the city ever experienced a real Ancient Mariner calm the air would be very murky ifideed. It may well be that it is the wind jWhich keeps Wellington as healthy, as it is. It was-calm again this morning, and there were belts of soot lying here and there on the harbour. The Harbour Board has again received complaints, the writers imagining that these black disfigurations of the surface are due to oil being put overboard from vessels, in the harbour. Whoever .is to blame for them, investigations made repeatedly by the board have proved that they are not due to oil, but that they, are just soot. Here again wind would soon, remove the soot by sinking it with a jobble. Sources of soot have not yet been the subject of a general inquiry. The destructor at the Corporation, yard contributes some, until: recently the Harbour Board's plant near the railway station helped to dun the sk£, and there is always a good deal of smoke over the big railway yard. Ships themselves do not produce much smoke unless they are moving out, but the thousands of chimneys" during the winter give out quite' a y large proportion of the smoke of Wellington, which on these still days helps to intensify harbour fogs. Householders would find it hard to remember when their chimneys were inspected, though most householders see to it themselves every year or two. Winter gales will probably shortly remove the causes of complaints about* spot.

Perhaps the most interesting point about the sooty deposits is their definite formation, in long streaks. Such disfigurations of calm harbour waters are common in.windless weather. Apparently what happens is that the soot falls during the night through being weighted with dew, ■ and in the absence of other influences would simply be spread evenly and inconspicuously over the water. But the temperature of the water varies from place to place, and wherever there is a warm patch a local stream of warmed air flows upwards. This creates a vacancy which is filled by air flowing in horizontally, and the soot is thus swept into comparatively thick masses.