66 Account of a Halo observed at Pictou, Nova Scotia. 
ring B appeared to be in proportion to A as 3 to 2; ring C 
had the same diameter with A; rings D and E the same 
diameter with B, and the ring F double the diameter of B. 
The rings A and C, and the rings A and B, at the points 
where they intersected, and the arcs D and E, were prisma- 
tically coloured ; the other parts, and the ring F, were white. 
No mock suns were visible at the points of junction of the 
rings ; but the rings were at these points somewhat flattened. 
« At 32 P.M., the rings B, C, D, and H, had nearly disap- 
peared, and the ring F became perfect ; and, at 4 P.M., all the 
rings had gone off, except A, which continued until near sunset. 
‘« Barometer 29°84 in. ; thermometer 75° in the shade. Wind 
gentle, from north-east; cirro-stratous clouds from north- 
east, and cumuli rising from south-west near the horizon.” 
Fig 1. Fig. 2. 
fe 
Horizon Brera 
Lorizonies 
Halo observed at Pictou, Nova Scotia, August 23, 1849. 
Fig. 2 represents the halo, as drawn by the writer at Pic- 
tou, with the aid of sextant measurements, made by Mr 
James Yorston of this place, and the following are the notes 
taken at the time :— 
“ The altitude of the sun, at 33 minutes past 3, was 
33° 40’ 30”. The wind was light, and from the north-west ; 
and the sky was covered by a thin cirro-stratus, curdled into 
small patches, and distinctly, though irregularly, fibrous. 
This cloud appeared to be the seat of the luminous rings. 
“The circle A had a diameter of 45°. Its upper part was 
bright, and shewed the prismatic colours, and it became gra- 
dually fainter towards its lower or western side. This I 
have endeavoured to represent in the figure by the shading, 
