200 



MAGNETIC DISTUKI5ANCKS AND AURORA 



August 14, 1903. 



2.0 a.m. Very faint, but extensive, aurora. 

 1'ati 'lii's scattered about asymmetrically from N. 

 boS.S.W. 



Between 1.57 and 2.12 a.m. V first fell 15y and 

 thru rose 25y. This was accompanied liy a sharp 

 oscillation in the H curve, consisting of a fall of 

 38y, followed l>y a rise of 30y. There was also a 

 to-and-fro movement of fully 15' in D. 



Subsequent to 1.30 a.m. there was a good deal of oscillation in all the curves during the whole forenoon, 

 and some of the U and H changes were decidedly more striking than those specified above. 



./</">/ 26, 1903. 



From 7.0 to 7.50 p.m. brilliant aurora was 

 observed. Started with rays showing up above 

 the hills from N. (magnetic) all the way round to 

 S. (magnetic) (28 E. of S. to 28 W. of N.). Some 

 of these rays were exceptionally long, extending, 

 in some cases, to an arc of 50 vertically. The 

 display seemed to have no special form. All 

 manner of sinuous evanescent streamers, arcs, &c., 

 were observed. 



At about 7.35 p.m. one streamer, or ray, about 

 1 in width, extended vertically above Observation 

 Hill (a little to E. of S.E.) to about 83 in altitude. 

 This is the longest ray we have observed. At 

 7.40 p.m. a winding streamer, or curtain, appeared 

 in the "Gap" (or about E.S.E.) and extended to 

 about 45 in altitude. This was the most brilliant 

 part of the display and was about equal to a star 

 of the 2nd magnitude. 



At 7.50 p.m. the display had almost dispersed, 

 but remained faint and very diffused, like a kind 

 of light luminous mist for some time after. 



There was a very large magnetic disturbance 

 commencing about 6.46 p.m. To all appearance 

 the first part was of the special type (Chapter X), 

 but as the V magnet was out of action, this is 

 not absolutely certain. 



Between 6.40 and 7.35 p.m. the D and H 

 magnets each executed a large to-and-fro move- 

 ment, on which were superposed numerous smaller 

 and very rapid oscillations. 



Both curves got beyond the limit of registiaiimi 

 in the direction of element diminishing, so that 

 the time of the turning-point cannot be fixed 

 exactly, but it was within a few minutes of 7. 15 p.m. 

 The to-and-fro movements in D exceeded 105' and 

 120' respectively. The to-and-fro movements in 

 H were equal and fully lOOy. The rise to the 

 maximum at 7.35 p.m. was very rapid, and after 

 the maximum there were extremely rapid move- 

 ments in the opposite direction, D falling 54' and 

 H falling 45y in about Lj minutes of time. 



Another way of putting the facts is that in the 

 course of about 3 minutes synchronous apparently 

 with the existence of the very long auroral 

 streamer D rose and fell 54'. 



After 7.37 p.m. there were oscillatory move- 

 ments in D, but of a much less striking character. 

 The H trace was highly oscillatory from 7.40 to 

 8.0 p.m. 



