appears to subsist between it and the Formation of Clouds. 31 



frosty, with dark cirri or cirrostrati upon a hazy but decidedly 

 luminous ground, extending from W.S.W. to E.N.E. These 

 covered the sky to an elevation of about 30° above the N.N.W. 

 point, and were affected by very rapid pulsations, propagated 

 apparently in a W. to E. direction. A similar appearance, 

 though not so distinctly marked, was seen in the South, the 

 remainder of the sky being quite clear. 



" November 19, 3 h p.m. A few cirri, rather irregular, but with 

 a tendency to a N.N.W. to S.S.E. direction. They moved slowly 

 from W.S.W. 7 h 50 m p.m. A bank of clouds along the S.W. 

 horizon, remainder of sky clear. Auroral column shooting up 

 from the E.N.E. point as far as Auriga. 8 h 10 m p.m., and for 

 several minutes before and after, sky as before. A splendid 

 luminous arch extended unbroken across the sky from W.S.W. 

 to E.N.E., varying in width and brightness at different parts of 

 its course, and also from instant to instant. Near the zenith its 

 width varied from 2° to 8°. Pulsations passed along it from W. 

 to E. Its centre crossed the magnetic meridian at an altitude 

 of about 78°, passing over Altair, Arided, Capella, &c. No other 

 auroral appearance visible. I was now called away for ten 

 minutes, and on returning to the open air found the whole sky 

 covered by patches of luminous clouds affected by rapid pulsa- 

 tions propagated from W.S.W. The arch, though still distin- 

 guishable, was now very faint and hazy. A small but very bright 

 aurora cloud appeared in Cassiopeia, and then suddenly moved 

 2° or 3° to E.N.E., growing rapidly fainter and then disappearing. 

 The sky was now obscured by clouds approaching to the cirro- 

 stratus type, between which the auroral light shone, chiefly, 

 however, to the west, there having as yet been no appearances 

 of the aurora in the usual quarter (N.N.W.). So suddenly was 

 the sky obscured by the clouds in question, that they must cer- 

 tainly have been formed on the spot by the electric or electro- 

 magnetic influence, and not brought over by atmospheric cur- 

 rents. The air was nearly calm, except for a few gusty breezes 

 from S.W. A thermometer rose 2° in 20 minutes, and another 

 exposed freely to the sky rose 4° in the same time. At 9 h p.m. 

 the former thermometer marked 352°, and the latter 32°, having 

 risen 6° within an hour. After this the clouds cleared off, with 

 the exception of irregular banks of cirrostrati in E. and W., 

 showing a few streaky lines ranging about N.W. to S.E. The 

 thermometers at 10 h p.m. indicated 33° and 26° respectively, 

 or nearly the same as at 8 h p.m. The auroral light was now con- 

 centrated in the usual quarter in an arched mass, the apex of 

 which bore N.N.W. altitude 14°. A few patches of dark clouds 

 moved from W. to E. within the luminous space. ll h 20 m . Sky 

 quite clear, with a very faint auroral light just above the N.W. 

 point, Air quite calm, frosty. 



