﻿115 



1903. 



Aurora display at 2h. 10m. a.m. Exceptionally bright, and one of the most interesting 

 yet observed. At about 2h. 15m. a.m. a huge arc extended from S.W. magnetic to nearly N. 

 magnetic. Apex about 25° in altitude, width 2°, inner part near horizon brightest and sharply 

 defined. Intensity of light at times nearly equal to that of a star of 1st magnitude. Coloixr 

 light j'ellow and straw and sometimes tinges of green, but never any indication of red or pink. 

 Movement very gradual from horizon towards zenith, and at times rapid lateral movement in 

 light from E. to W. (true). Arcs and intensity of light most evanescent, oidy lasting a few 

 minute.s, but rapidly appearing again in other directions. 



At 2h. 20m. two arcs formed over Observation Hill, altitude 20° to 30°, width 1° to 2°, and 

 remained fairly bright for a few minutes, but quickly faded away again. Brightest patches 

 of aurora were in S. and S.W. magnetic. Very few streamers and vertical shafts. Light was of 

 a diffused nebulous nature. The apex of the whole phenomenon, which consisted of arcs and 

 fragments of arcs, was in N.W. magnetic. Altitude from 15° to 30°. Display had nearly 

 disappeared at 2h. 40m. a.m. Absolutely no sign of auroral light in sky at 3h. a.m. Placed 

 prismatic camera on ship's rail and exposed plate to part of sky where light was brightest. Left 

 exposed for nearly 8 hours. 



May 31. — (Plate 13.) 4h. p.m. Two large arcs rising in the S. formed of diffused and exten.sive vertical 

 rays of light. The arcs rose at an angle of about 45° to 60° to the horizon, but gradually 

 became more vertical and folded upon themselves at intervals, and then the eastern ends began to 

 form a corona around the zenith, the easternmost of the arcs folding round the zenith to the 

 right, the southernmost folding round to meet it to the left. Movement sideways slow, vertically 

 rapid. Intensity bright as it rose to the zenith. 



June 1. — 2h. a.m. Very faint auroral glow and curtain 3° S. of Observation Hill (true), and altitude 15°. 

 4h. a.m. Very faint auroral streamer from zenith to N. by W. horizon (true). Tempera- 

 ture, - 19° F. Wind E., 5. Clear sky. 



June 2. — Overcast during most of night. 



6h. a.m. Fine aurora S.E. to N.AV. (true), most brilliant N.W. Rapidly fluctuating curtains 

 and isolated streamers. Some isolated patches passing to near zenith. Temperature, - 23° F. 

 Wind E. by N., 5-6. b. 



Midnight. Low aurora in the N., vertical streamers just appearing above the hills, very 

 vivid greenish light, little motion. - 24° F. Light E. airs. b. 



Jime 3. — 2h. a.m. Extensive aurora, at times brilliant and with much diffused light all over the heavens. 

 There was a succession of curtains rising from the E., touching the horizon at N. and S., and 

 crossing the zenith towards the W. in the form of very large arcs. These curtains seemed 

 broadside on while low down, and gradually narrowed as they rose toward the zenith, appearing 

 to be seen edgewise when overhead. There were sometimes four or five curtains rising one above 

 the other. None passed more than 10° or 20° to the W. of the zenith, becoming there dift'used 

 and waxing and waning in intensity, apparently with the force of the wind, which was somewhat 

 squally, force 1-3 E. Temperature, -21° F. b. 



2h. 15m. a.m. to 2h. 30m. a.m. extensive are. At first apex 5° or 6° E. of zenith, which 

 gradually moved up into zenith. Breadth 2° to 3°. N. and S. extremities of arc to within 

 30° of horizon on each side. Intensity of light at times fairly strong, 10 '5 on wedge 

 photometer, which value just eclipses a Centauris. Light diffused and no vertical shafts. 

 Phenomenon had entirely faded at 2h. 30m. a.m. Exposed spectrum plate for some hours. 



4h. a.m. A faint curtain of vertical streamers, about 8° altitude, in the E. true, and s, 

 nebulous streamer somewhat higher toward the N. Wind N.E., 2. - 22° F. b, 



Q 2 



