202 
The N.Z. Journal of Science and Technology. 
[Aug. 
Second (Main) Storm. 
May 14 d. 22 li. 13 m. 
May 15d. Oh. 15m. 
15d. 5h.30m. 
15d. 4h.42m. 
15 d. 5h. 30 m.— 
15d. 5h. 30m, 
10 h. 30 m. 
Sudden commencement of the principal storm 
with a sine-curve motion in H and Z, of about 
two hours’ duration. Amplitude in H, — 150y \ 
in Z, 100 y. 
Beginning of the fall to a minimum in H. At this 
time H = 0-35220 ; Z = — 0-20350. 
Min. H — 0-34300. 
Min. Z = —0-20270. 
5h. 45m. Sudden fall in Z. A Z = — 65y. 
Beginning of recovery in H. 
Change of velocity in recovery of H, and. beginning 
of a comparatively quiet period. Between maxi¬ 
mum at Oh. 15m., and minimum at 5h. 30m., 
A H = 920 y, and A Z = — 75 y. 
Third Storm (Repetition of the Main Storm). 
May 16 d. 1 h. 27 in. Sudden commencement. A H = + 20y; A Z — 
— 10 y. 
10 h. Minimum in H. H = 0-34875. 
13 h. Beginning of a quiet period. A H, max. (2h.) — 
min. (lOh.) = 160y. A Z, min. (2h.) —max. 
(7h.) = —60y. 
May 13d.—16d. H max., 13d. 13h. 9m. H = 0-35305. 
H min., 15d. 5h. 30m. H = 0"34300. 
A H = 1000 y. 
Z max., 15d. 4h. 42m. Z = — 0-20270. 
Z min., 15d. 10h. 40m. Z = — 0*20427. 
AZ = 157 y. 
On May 15 d. 5§h.-6jh., Greenwich (6.15-7 p.m., May 14, local mean 
time), a display of the aurora australis was observed at this Observatory. 
There is a range of mountains from 600-700 m. high to the south, distant 
about 10 km.; and above this the light could be seen in the form of a 
segment of a circle, and reaching to an altitude of 22° determined from 
star positions noted. It covered probably an arc of about 25° along the 
horizon, and the centre was apparently close to the magnetic meridian. 
In spite of the moonlight (first quarter), and a little twilight as well, the 
light was very conspicuous and of a glowing red colour. The point of the 
greatest intensity appeared to move from east to west at about 6h. 20 m, 
Greenwich time, and traces of a brighter yellow-coloured streamer were 
noticed at the same time. The sky was quite free from cloud at this hour; 
later on some small fracto-cumulus were experienced, but no cirrus clouds 
were seen. No signs of the light were seen after 7 p.m. 
Reports from Tongatabu, 7° south of Samoa, state that the light was 
observed there also to the south. A very bright display was also seen in 
New Zealand. 
The wireless station in Samoa was in communication with New r Zealand 
during the time of the aurora, and the conditions were considered to be 
unusually good. 
At local noon on May 14 three spots were observed on the sun, two of 
them close to the centre. This time is not far away from the time of com¬ 
mencement of the greatest disturbance. These two were certainly large 
spots, but were not thought to be of the largest type. 
On May 20 a period of thunderstorms, exceptionally frequent and heavy, 
began, and continued for more than a week. This is unusual in Samoa, 
especially at this time of year. 
