. 
24 REPORT—1852. 
METEOROLOGY. 
Account of a remarkable Case of Mirage. By Sir Daviw Brewster, K.H., 
D.C.L., F.RS., § VuPRS. Edinb. 
On the 21st of August, 1851, Miss F. E. went out on a drive with Mrs. and Miss 
H., and leaving them ‘in the carriage, climbed to the top of the Mynydd, a high and 
steep hill, rising about 500 feet above the valley of New Radnor, the summit round 
and bare, the ground firm. 
It was about half-past 2 p.m., and there was a bright hot sun. 
After picking some flowers on the top of the hill, she went to a spot whence she 
could see the road, the carriage and the ladies, and waved to them her “ victorine,” 
which she held in her hand. Then, turning, she suddenly perceived a figure at the 
distance of a few yards from her. It was standing on a wet spot, where there was 
a little thin mist (probably steam) rising, and wavered a little, never remaining still ; 
for which reason she did not think it was a real figure, though she says it had “a great 
deal of bulk,” It was on a level with herself, and formed a species of triangle with 
herself and the sun, F. looking towards the sun, but not directly to it. She thought 
at first that the figure might be a delusion; it stood exactly facing her, and she first 
discovered it to be her own image by perceiving that, like herself, it held a “ victo- 
rine”’ and bunch of flowers in its hand.- She moved the hand with the nosegay, and 
the figure did the same. The dress and the flowers were precisely similar to her 
own, and the colours as vivid as in the reality. She could see the colouring and 
the flesh; it was like looking at herself in a looking-glass. 
She stood looking at and examining it for two or three minutes; then, hecoming 
frightened, turned away from the figure and ran straight down the side of the hill 
(which, though covered with turf, is of almost perpendicular steepness) without look- 
ing behind her, to Mrs. and Miss H., to whom she said that she had ‘had such a 
strange companion on the hill—herself.”” There was no mist around her when she 
saw the figure; it hung only over the one spot. 
Miss H. said, that she and her sister-in-law had remained in the carriage. Look- 
ing up, she saw two figures on the top of the hill against the sky, at a few yards’ 
distance from each other. Being short-sighted, and the distance considerable, she 
could distinguish nothing but this fact, and merely observed, that she wondered 
what companion F. had met with. She then turned to talk to her companion, and 
thought no more about the matter, until F. came running to them, considerably 
alarmed, to tell them what she had seen. Mrs. H. saw the two figures as well as 
her sister-in-law. 
A little servant-boy who was with the carriage, saw F. run down the hill, falling 
repeatedly, and appearing much frightened. 
Miss F. E. returned a few days after to the same spot to see whether the appear- 
ance would be renewed, but has never seen it again. 
The figure of Miss E., thus distinctly seen by herself and others, was obviously 
produced by reflexion from the mass of vapour rising from the wet ground on which 
she stood. Sir David Brewster stated, on the authority of direct experiment, that 
when the particles of vapour are sufficiently small, such as that produced by breathing 
on a glass surface of nearly the same temperature as the breath, the surface of the 
vapour reflects as distinct a picture as if it were the surface of water. The vapour 
surface must have been considerably extended in the direction of Mrs. H.’s carriage 
in order that the reflected rays might reach it. 
On certain Phenomena of Diffraction. By Sir Davin Brewster, K.H., 
DCL, FRS., & VuPRS. Edinb. 
In this communication the author pointed out some new and interesting phzno- 
mena which he had observed. The diffracting body tapers like the point of a very fine 
needle, which will be understood from the figure, which very imperfectly represents 
the internal and external fringes as produced by a needle-point like MN. The ev- 

