238 Meteorological Observations for July 1831. 



METEOROLOGICAL OBSERVATIONS FOR JULY 1831. 



Gospoii: — Numerical Results Jbr the Month. 



Barom. Max. 30-348. JulyG. WindN.E.—Min. 29-606. July 13. WindS.E. 

 Range of the mercury 0-742. 



Mean barometrical pressure for the month 29-999 



Spaces described by the rising and falling of the mercury 3-190 



Greatest variation in 24 hours 0-259. — Number of changes 15. 

 Therm. Max. 79°. July 9. Wind W.— Min. 52°. July 3. Wind W. 

 Range 27°. — Mean temp, of exter. air 64o-68. For 31 days with in 5563-40 

 Max. var. in 24 hours 22°-00.— Mean temp, of spring-water at 8 A.M. 51-81 



De Luc's Whalebone Hygrometer. 

 Greatest humidity of the atmosphere, in the evening of the 23rd .... 100° 

 Greatest dryness of the atmosphere, in the afternoon of the 9th ... 43-0 



Range of the index 57"0 



Mean at 2 P.M. 55°-2.— Mean at 8 A.M. 61°4.— Mean at 8 P.M. 67-5 



of three observations each day at 8, 2, and 8 o'clock 61-4 



Evaporation for the month 4-55 inches. 



Rain in the pluviameter near the ground 3-465 inch. 



Prevailing winds, West. 



Summary of the Weather. 

 A clear sky, A\; fine, with various modifications of clouds, 15^; an over- 

 cast sky without rain, 74 ; rain, Sj. — Total 31 days. 



Clouds. 



Cirrus. Cirrocumulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus. 



23 16 27 3 28 23 16 



Scale of the prevailing Winds. 

 N. N.E. E. S.E. S. S.W. W. N.W. Days. 

 2 4 U 6 U 6 8 24 31 



General Observations. — This month has been fine, with the exception of 

 four or five days, \xlien much rain fell here. In the evening of the 5th, 

 Venus was in conjunction with a Leonis, and they formed a small isosceles 

 triangle with Saturn. At midnight of the 8th several flashes of lightning 

 ascended from the horizon in the north-east quarter. The 9th was the 

 hottest day in the shade, and there were a few flashes of lightning in the 

 night in the south-east horizon. Sheet lightning also occurred the fol- 

 lowing evening. Much rain fell on the 11th, 12th, and 14th, which was 

 accompanied with lightning and thunder. Distant thunder and lightning 

 also occurred in the afternoons of the 16th and 28th. In the afternoon of 

 the latter day the edge of a thunder-storm passed this place, and proceeded 

 with some violence in its electrical efltcts in the direction of Berkshire. 

 Not only in Hampshire, but in most other counties, thunder-storms have 

 often occurred through the month, so that the period may be said to have 

 been a \uar of the elements. 



On the 19th, 20th, 21st, and 22nd, a hard gale blew from the South- 

 west, and on the following day it blew equally hard from the opposite 

 point of the compass, with a copious rain, and a considerable decrease in 

 the temperature of the air. 



The rain and wind lodged some of the corn in this neighbourhood. 



From the 25th to the end of the month the weather was dry and warm, 

 and on several days a thermometer in the sun's rays rose to 120 degrees, 

 which had the effect of ripening the wheat, and harvest commenced here 

 at the close with every prospect of good average crops. 



Soon after ten o'clock in the night of the 30th, an aurora borealis ap- 

 peared, whose upper arch, though not well defined, was about 16 degrees 



high 



