as Harbingers of falling Weather. 503 



less, and there was every appearance of continued heat and 

 drought. 



On the following day (28th), at 5 p.m., we were visited 

 with a very smart shower, with thunder and lightning at a 

 distance. [This shower had so limited a range westward of 

 London, as not to extend to Bayswater ; at Camden Town, 

 northward of London, there was profuse rain.] 



In the evening previous to the appearance of the solar halo, 

 I observed a beautiful meteor pass just below Benetwasch in 

 the tail of Ursa major : it took a south-easterly direction ; its 

 colour was first faint blue, which faded off into pale yellow. 

 Several " shooting stars " were also visible. 



In the evening of the 27th, there was (after sunset) a 

 beautiful display of lightning, or ignited vapour, playing about 

 in the s. : not a vestige of a cloud was visible. During this 

 luminous display, the wind, which had been stationary for 

 the last 7 days in the e., veered round to s.w. On the 28th* 

 the wind became greatly disturbed during the shower, and 

 not only completely surrounded the compass in a few hours, 

 viz. from s.w. to s.w. again, but finally became settled in the 

 e., the point of its station in which I first observed the 

 halo. After this convulsion, the evening was clear and calm. 

 Now, although I have not yet seen any meteorological re- 

 ports of the latter part of July, yet I have no doubt the power- 

 ful indications which I witnessed will be verified as to the 

 results, upon the simple principle of cause and effect. 

 The maximum heat during the month of July was on the 

 20th ; the thermometer being nearly 92°, one degree higher 

 than June 10th. The minimuitt temperature during the night 

 of the 20th was 67°; being 14°* higher than the extreme heat 

 of June 25. 



From repeated observations, during a period of more than 

 ten years, I conclude that both solar and lunar haloes are 

 heralds of succeeding changes of weather from dry to moist ; 

 as rain generally follows in periods of from four to twenty- 

 four hours after each manifestation, according to the brilliancy 

 of its appearance, and the perfection of the halo, particularly 

 if the wind be s. or s.w. And that these indications generally 

 precede the indications of the barometer, may be accounted 

 for thus : — As the lower stratum of the atmosphere becomes 

 condensed (from contrary currents or other causes), it is 

 better qualified to concentrate by reflection the rays of the 

 sun or moon ; and hence a halo is formed before the atmo- 

 spheric pressure is sufficient to act upon the barometer. 



Lunar haloes are more easily discovered than solar haloes, 

 because the lunar rays are more feeble than the solar ; but 



