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Devereux. — Rainfall and Meteorology of Waihi. 409 



that the wind-force of both systems is neutralised. Tiiis fusion is an 

 important factor for heavy rainfall, and will be referred to in greater detail. 



The easterly winds of an energetic anticyclonic system often bring 

 heavy falls, for the moisture which they gather from the sea is deposited 

 on the windward slopes of the ranges. 



Heavy rain from the west is the exception, for the winds of a depression 

 passing westward appear to have deposited much of their moisture on the 

 high country of the western Waikato and on the windward slopes of the 

 Te Aroha Eange. 



Another feature well known in the meteorology of the Dominion is the 

 passage of a series of wave-pressures from the west. These waves bring 

 remarkably changeable weather. The winds range from between west- 

 north-west and north-west and west and back again towards the west, 

 these changes sometimes occurring rapidly. Pressure is also oscillatory, 

 sometimes in a marked degree. 



Having described the systems which govern the climate, and the topo- 

 graphical features, further and detailed reference will be made to the intense 

 nature of the rainfall. 



The records have been criticized with some scepticism, and it is well 

 to record the fact that for some years two gauges have been exposed — 

 an ordinary funnel-and-bottle pattern, and a Lander and Smith automatic 

 recording, eight-day-clock movement — one gauge checking the other. 



The most prolonged precipitation recorded since 1898, when the observa- 

 tions commenced, was that of January, 1907, when 21^ in. fell in nine days. 

 The records of the Meteorological Office showed the passage of a cyclone of 

 great area from the neighbourhood of Norfolk Island, between the North 

 Island and the Kermadecs. The cyclone had two minima, and great floods 

 were experienced over the Auckland Province — Waihi's total for the month 

 was 25 in., the biggest individual to al for that notable period ; Tauranga's 

 total was 20-94: in. ; Auckland's approximately 8 in. 



The two most remarkable falls recorded locally occurred during the 

 present year, and invite special comment. The first was recorded to 29th 

 March, and the second to 3rd July. The rates of fall are shown in the 

 diagram on p. 410. 



In the first instance, the fall of 29th March was due to the passage of 

 a cyclone of unusual extent, which approached East Cape from about north, 

 and. traversing the east coast of both Islands, caused very heavy falls. The 

 barogram of the 29th was remarkable for its waviform trace, and it may be 

 that the air-waves propagated by such a disturbance can be transmitted a 

 very considerable distance. The rainfall was intense within certain limits, 

 as the rates show ; the heaviest precipitation appears to have been con- 

 fined to the coastal hills. A visit to the coast soon afterwards showed the 

 tremendous nature of the fall, which must have been double that which 

 was recorded at the station, three miles and a half distant. In one par- 

 ticular valley the destruction was unique. Residents state that the water 

 came down in a wall 20 ft. high, bringing with it large trees with the soil 

 adhering to the roots ; large boulders, one weighing over a ton ; and 

 thousands of yards of soil and gravel. Most of the debris was carried right 

 down to the sandhills, through which the stream had cut a fresh outlet. 

 It was evident that the damming-up of watercourses and the subsequent 

 release of the obstructions was not the sole cause of the remarkable damage : 

 eye-witnesses state that the rain was flowing down the slopes in cascades. 

 At 1 p.m. there was a single electrical discharge on the coastal range of 



