368 Dr. Barney on some Atmospheric Phenomena [Nov. 



o, Road near Citernon. 



p, Bridge de la Pyle on the Ain. 



q, Highest part of the road. 



r, Orgelet. 



s, Mount Tourget. 



t, Highest point of the road . 



u, Ditto. 



v, Lons-le-Saunier. 



■a; Plateau Calcaire. 



y, Chateau Mirebel (signal). 



A B, Syphon barometer, constructed at Berne, in 1811, by 

 Noseda, a pupil of Paul, of Geneva ; and employed in 1811 and 

 1812 in the barometrical measurements executed by M. Delcros 

 in Alsace and in Switzerland. 



G D, Profile of the tube without the mounting. 



Article VI. 



Remarkable Atmospheric Phenomena and their Effects. 

 By Dr. William Burney. 



Gosport Observatory, Sept. 24, 1818. 



Since the commencement of autumn, considerable changes 

 have taken place in the atmosphere from a dry to a humid and 

 electric state, and the temperature has consequently been very 

 much diminished. 



On the 1st inst. we had a storm of rain, hail, thunder, and 

 lightning ; the latter continued very strong and vivid from two 

 till half-past four, a. m. while the thunder proceeded in a north- 

 west direction. On the 5th, P33 inch of rain fell, which is as 

 much as had fallen here during the preceding 16 weeks. 



16th. — At a quarter before eight, p.m. a large lunar iris 

 appeared on an extensive Nimbus to the west, the harvest moon 

 being in the east, nearly full, and about 10° above the horizon ; 

 in 15 seconds after, it was well formed by refraction and the 

 reflection of the lunar rays through the falling drops of rain, the 

 moon was eclipsed by a dark passing cloud, and the phenomenon 

 disappeared instantaneously. There was no time to measure it, 

 but the semicircle appeared nearly as large as the solar rainbow 

 under-mentioned. 



21st and 23rd. — We had strong equinoctial gales rising from 

 the south and south-west soon after sun-rise, and dying away at 

 sun-set. 



A solar halo appeared on light vesicular vapour on the 1st, 6th, 

 14th, and 22nd, and a lunar halo in the evening of the 17th ; 

 three of them were 44°, and two 45° in horizontal diameter, 

 their perpendicular diameters being somewhat greater j and 



