108 Trans. Acad. Sct. of St. Louis 
ern edge defined sharply but its eastern edge very indistinct; it re- 
mained visible for about one hour and twenty-five minutes. Fi ig. 4.) 
10:35 P. M. The most active period of the display began, when 
a very sudden increase in brightness set in. Great streamers of 
white light appeared, many of which ‘were over forty degrees in 
length, some narrow and some wide. At first the activity centered 
in the west, then He the east, followed by even greater activity at 
the middle of the arch, and finally the rays blazed forth all along 
the arch. The greatest activity and brilliance came at 10:38 p. m., 
and for some minutes thereafter, when the whole area of the dis- 
play, even between the rays, glowed with a soft pearly light. (Fig. 
). No single — contd possibly see everything that was 
taking place; the events came in such rapid succession that observa- 
meridian, all the way to a Saint 15° above Polaris and about 53° 
above the horizon. It lasted fully five minutes. Another ray darted 
and Se pe an aL of 30° with the meridian. The upper 
tremity of this ray reached a point 3° west of Beta Ursae Winoris. 
Several long rays appeared along the eastern end of the arch, one 
of which crossed Lacerta and Cygnus to a point 3° = of Dene 
Most of the rays were now exhibiting colors; those near the en 
of the arch were pale rosy-pink, and those near the sane dilute 
green like the arch. A few were still white. The colors in man 
instances would come and go in cycles of a few seconds’ pee 
Many of the shorter rays were moving rapidly toward the w 
At one time there were no less than ten long rays iat looked “Tike 
great searchlight beams. 
= = = P.M. The rays became less conspicuous and most of the 
y ceased. The dark area below the arch Esppentet and the 
whales aurora looked much as it did before 10:15 p. m 
11:40 P. M. The area above the arch began to brighten and 
was soon as bright as the arch. Then it broke into a n of 
cloud-like parts, which were roughly oval in shape, but had some- 
