186 The N.Z. Journal of Science and Technology. [Aug. 
of the electric waves which constitute wireless telegraph and telephone 
signals is influenced by the nature of the country over which these signals 
pass, by the transition from daylight to dark, by variations in the ionization 
of the upper strata of the atmosphere, by rain, by wind, and, in fact, by 
meteorological conditions generally, it should not be surprising to find that 
the New Zealand wireless services were considerably affected by the violent 
electrical disturbances that accompanied the recent auroral displays. With¬ 
out going into detail, sufficient may be said to indicate in this connection 
the nature of the effects produced by the aurora. 
Effects of the Recent Aurora. 
Radio Coast Stations. 
The effects of the aurora upon wireless reception were felt by all the 
New Zealand wireless coast stations—-viz., Awanui, Auckland, Wellington, 
Awarua, and Chatham Islands. The Auckland Radio Station records that 
unusual variations in the signal-strength were noticed, beginning on the 
9th May, accompanied by what are known as “ hissing ” statics. At 
other stations the principal effects were noticed on the 14th and 15th May, 
tapering off on the 16th, and returning to practically normal conditions late 
on the 17th. 
At 1 p.m. on the 14th Awarua observed that the long-wave signals 
from the Awanui Station were very much above normal strength, and by 
4 p.m. a decided variation in the strength of wireless signals had been 
observed at all stations. At 5 p.m. Awarua (near the Bluff—lat. 46° 36' S.) 
noticed the first visible evidence of the aurora, and this was accompanied for 
a short period by a remarkably quiescent interval during which statics 
and wireless signals disappeared altogether. Shortly afterwards the signals 
emitted by the Wellington and Chatham Island stations became very weak 
and variable in strength, although signals from Auckland and the Australian 
stations were very little affected. Such conditions may be said to have 
prevailed generally until the evening of the 17th, when signals resumed 
their normal characteristics, but atmospheric disturbances continued for 
some time to be heavy and numerous. During the 14th, 15th, and 16th 
signals at all radio stations were very erratic, both in intensity and in 
uniformity. At one moment they would be normal or even above normal 
strength, while shortly afterwards they would be normal in one or more 
directions but weak and varying from other directions ; and this was the 
general experience throughout the whole period. A rather interesting 
phenomenon was that, while signals from New Zealand and Australian 
stations were subject to great variation, the signals from long-wave European 
stations did not appear to suffer any variation either in intensity or in 
uniformity. This is corroborated by Rarotonga (Cook Islands), which at 
times experienced variation in New Zealand signals but no variation in 
signals from northwards. Apart from the variations in the New Zealand 
radio signals, the only effect observable at Rarotonga was the prevalence 
of strong atmospherics during the auroral period. At Apia (Samoa) the 
auroral display was visible at 6.45 p.m. (Samoan time) on the 15th, and 
simultaneously the signals from Awanui on 2,000-metres wave-length were 
considerably augmented in strength, and for a short period were the strongest 
that had ever been received from that station. While stations in the North 
Island of New Zealand were fading and weak to South Island stations, they 
were of usual strength to Apia. Apart from these circumstances nothing 
unusual was observed by Apia. 
