appears to subsist between it and the Formation of Clouds. 33 



to E.N. E. At 9 h it passed over Arcturus, and on to eastward 

 so as to bisect obliquely a line joining the Polestar and the upper 

 Pointer. From this time to 9 h 10 ra it gradually moved to north- 

 ward. Its altitude above the N. by W. point was now about 44°. 

 Its breadth was about 3°. At one time it appeared double. Its 

 northern limb was well-defined and regular (with the exception 

 of a slight bend near the middle) . The whole sky to south was 

 covered with a sort of cirrous haze so dense as almost to oblite- 

 rate Jupiter, and a few cirrostrati were moving from about south. 

 The sky to north of the arch was perfectly clear, and^vithout the 

 slightest appearance of an aurora. At about 9 h 15 m the haze 

 cleared away from behind the arch, and it then was seen to much 

 advantage in the form of a well-defined luminousbelt of nearly equal 

 width (about 3°) throughout, along which pulsations (electric ?) 

 continually passed so rapidly that I could not be certain whether 

 they moved from W. to E. or from E. to W. The arch lasted 

 about thirty minutes. Its light was white and very splendid, 

 quite free from the yellow tinge which distinguishes the light of 

 ordinary aurorse. Its elevation also appeared to be much inferior 

 to that of any of the auroral arches resembling it in form, which 

 I have noted. Indeed I have doubts whether this phenomenon 

 should be classed with the aurora or with cirri. Its direction, 

 it will be remarked, was the same as that of the cirrous clouds 

 noticed three hours before. 



"September 2, 9 h 15 m p.m. Cirrocumuli forming in different 

 parts of the sky, and moving briskly from S.W. A fasciculus 

 of these during the process of formation was a very interesting 

 sight. It seemed as if a machine was at work in the upper 

 regions, turning off a series of flocculous bars of uniform length 

 and width, and strictly parallel to each other. These at length 

 amounted to about twelve in number, ranging in a N.W. or 

 N.N.W. direction, and moving briskly nearly at right angles to 

 this direction. A small insulated cloud of the same kind also 

 changed its form and size very considerably. The sky after- 

 wards became quite overcast, the clouds moving from S.W. with 

 a faint luminosity above them. The barometer which had been 

 high and steady now began to fall quickly, with a brisk S.W. 

 wind. 



" 1844. Feb. 25, 10 h 30 m p.m. Cirri extending from W.N.W. 

 and moving from the same point. Within half a minute some 

 hazy cirri (?), formerly so thin as to be scarcely perceptible, sud- 

 denly assumed the aspect of dense cirrocumuli moving fitfully 

 from W.N.W. The cirri were affected by luminous pulsations 

 distinctly observable, notwithstanding the moonlight. The cirro- 

 strati became denser and thinner by turns, and moved onwards 

 in an irregular manner, and as it were by fits. 



Phil Mag. S. 4. Vol. 6. No. 36. July 1853. D 



