510 Mr. J. Glaisher's Remarks on the Weather 



those situated north of Greenwicli being lower than at Gi'een- 

 wich, according to the difference of latitude and elevation. 



The mean monthly temperatures of the places in Cornwall 

 and Devonshire, in each of these three months, were above 

 those of other places. At Exeter, however, the values were 

 intermediate between those at places situated within these 

 counties, and those situated out of them in the same latitude. 



On March 29 a remarkable solar halo was seen from many 

 places in England, and in the Isles of Wight, Guernsey, and 

 Jersey. This halo, with its accompanying parhelia*, was well 

 seen, and the descriptions of the phiBUomena from different 

 localities agree better with each other than is usually the case 

 with these optical phoenomena. The following are the prin- 

 cipal facts: — 



1st. A coloured circle, whose diameter was 22% the centre 

 of which was occupied by the sun ; seen by all the observers. 



2nd. A colourless circle, whose diameter was 22°, the 

 centre of which was situated a little to the east of the sun; 

 seen by the observers at Guernsey and the Isle of Wight. 



3rd. A coloured arc of a circle, of which the sun occupied 

 the centre, whose diameter was 44°; seen at Oxford. 



4th. A large white brilliant circle, whose centre was the 

 zenith, passing through the sun; seen by all the observers. 



5th. There were on this circle four parhelia, two of them a 

 little beyond the first-mentioned circle, at its intersections with 

 the large white horizontal circle ; these were seen by most of 

 the observers. 



6th. There were two parhelia opposite to the sun, the one 

 above, the other below him, at the intersections of the 1st and 

 2nd described circles; seen at Guernsey. 



7th. The 5th and 6th parhelia were white; they were placed 

 on the circumzenithal circle, as near as I can tell, at the points 

 of intersections of a circle with a radius of 90°, with the sun 

 for its centre ; these were seen at Christchurch. 



8th. At the culminating point of the first-mentioned circle 

 there was a bright and coloured arc, which was concave 

 towards the sun ; this was seen at Christchurch and Oxford. 



9th. The observer at Guernsey f saw four arcs of circles, 

 one situated on either side of the two first-mentioned parhelia, 

 one below the parhelia mentioned in No. 6, and one near 

 the parhelia situated on the circumzenithal circle in the N.E.; 

 these arcs were convex towards the sun. 



10th. There were two coloured arcs of circles, convex 



[* For a descii|)tion ofthis halo with its accompanying parhelia, as seen at 

 Portsea, see p. 434 of the [)risent volume of this Journal. — Ed. Phil. Mag."] 



t The appearance of the halo, as seen at Guernsey, was engraved in the 

 Illustrated London News of April 8, 1848. 



