398 Scientific Intelligence. [May, 
February.—Mean pressure of barometer, 29°658; max. 30°61 3 
min. 28°90. Range, 1:71. Spaces described, 13°32 inches. 
Number of changes, 24.—Mean temperature, 41°82; max. 53; 
min. 3). Range, 22°.—Amount of snow and rain, 1°34 inch. 
Total this year, 2°65 inches.—Wet days, 6; cloudy, 13; fine, 9. 
—Prevailing winds, W. and S.W. N. 2; S. 2; S.W.6; W. 15; 
N.W. 2; Var. 1. Number of windy days, 153; boisterous, 6.— 
Mean of the liygrometer, 693. 
The barometrical column during the whole of this month has 
been incessantly in motion, as will be seen from the number of 
changes in its direction, which are nearly equal to the days in the 
period. ‘The range was confined to four days, viz. from the Ist to 
the 4th ;on which last-mentioned day it was depressed nearly a full 
inch ; but on the 10th, having nearly regained its former elevation, 
a violent storm.of wind and rain from the N. on the 11th caused 
another depression of nearly an inch and a quarter. 
The temperature for the most part has been very high for the 
season, and the variations trifling ; indeed, in the minimis there 
has been a very sensible approximation to the mean. 
The amount of rain nearly agrees with that for the last month: 
the greater part having fallen by night. 
A very brilliant and splendid display of the Aurora Borealis was 
observed here in the evening of the Sth, and was followed by much 
wind and heavy rain. On the 25th and 26th, between eight and 
nine, p.m. the moon exhibited a very bright corona, encircled by 
a distinct double halo, which continued each time above two hours. 
These appearances were succeeded by a most tremendous hurricane 
from the W. during the whole of the 27th, accompanied between 
five and six, a.m. with loud thunder and vivid lightning. A very 
large solar halo appeared on the 21st, and was almost immediately 
followed by a violent gale from the S.W., and the heaviest shower 
of snow, mixed with hail, we have observed during the present 
winter. 
New Malton, Feb.'2, 1817. J.S. 
Hil. On the Rat d’eau. 
(To Dr. Thomson.) 
SIR, 
I hope you will not regard the following observations on a sin- 
gular phenomenon obtrusive, and unworthy a place in your 
Journal. 
The phenomenon to which I allude*has, I believe, been described 
by travellers before; but as it occurred to me during a recent tour 
through the South of France, I cannot resist the temptation of 
offering you a few desultory remarks upon it. Ne’ 
I refer to that singular occurrence in the river Dordogne which is 
commonly called the mascareé, and which is known in that part of 
France by the name of the raé d’eau. Major Rennel, in his account 
of India, has mentioned a similar phenomenon having been ob- 
