34 Mr. W. Stevenson on the Aurora, and the connexion which 



"Aug. 31, 9 h p.m. Cirrostrati spread over the whole sky in 

 bands stretching from W. to E. Above these were fleecy cirri, 

 which underwent rapid and frequent changes in density, lumino- 

 sity and form. Sometimes luminous patches would form in an 

 instant and then as suddenly disappear. Cirrous streaks also 

 appeared and disappeared in the same manner. The clouds 

 moved from W.N.W. 



"Sept. 29, 9 h 10 m p.m. Auroral arch in N.N.W. about 2° 

 or 3° broad, the apex about 25° above the N.N.W. point. 

 Within it were a few faint streamers. In a few minutes the 

 upper part began to assume a cirrous appearance and to move 

 towards the zenith. Cirrous streaks then began to form within 

 the arch, and in a short time (9 h 45 m ) all the space which the 

 aurora had occupied was covered with compact, luminous, and 

 fibrous cirri, the aurora having passed by degrees into this con- 

 geries of cirrous clouds. The cirri moved briskly from about 

 N.W., their fibres ranging N.N.E. to S.S.W. They formed a 

 47° halo in passing over the moon. 10 h 30 m p.m. Clear, slight 

 auroral haze in N.N.W., cirri moving from N.W. ll h p.m. Sky 

 perfectly clear and no appearance of aurora. 



"Nov. 16, 10 h 15 m p.m. Cirrostrati from N.W. to S.E. Sky 

 obscured by a cirrous haze, which in several places was con- 

 densed into patches of cirri or cirrocumuli. Auroral luminosity 

 in N.N.W., from which luminous undulations passed with great 

 rapidity up to the zenith, and were even perceptible over the 

 whole sky, though they all originated in N.N.W. In a few 

 minutes the haze under the influence of these pulsations assumed 

 a more decided cirrostratus character. The auroral light was 

 not very intense, but the pulsations were very distinct, and 

 seemed to traverse the whole sky instantaneously. 



" Nov. 22, 8 h p.m. Brilliant streamers shooting up towards the 

 zenith in the usual manner. 8 h 15 m . No auroral appearance 

 visible, fleecy cirri moving from S.W., and at a greater height 

 fibrous cirri moving from S., the fibres ranging W. to E., or at 

 right angles to the direction of the line of motion. These were 

 affected by luminous pulsations similar to those *of the aurora ; 

 they had not, however, such a yellow tinge. The cirri under- 

 went considerable changes in a very short time. 



" Dec. 7, 9 p.m. Sky clear. Cirrostrati suddenly began to form 

 simultaneously in different parts of the sky, and at length formed 

 a broad band extending from N.W. to S.E. A slight haze first 

 appeared which became denser, until it at length assumed a well- 

 defined cirrostratus appearance. During the formation of these 

 clouds the thermometer rose from 27° to 29°. 



"Dec. 29, 2 h p.m. Cirri moving briskly from W.N.W., their 

 ' fibres ' being distinct N.N.E. to S.S.W. 4 h p.m. Cirrostratus 



