

Meteorological Summary for 1823. — Hampshire. 157 



Least monthly quantity in January . . . 0*63 In. 



Total amount for the year 24*28 



Main. Inches. 



Greatest monthly quantity in October . 4*820 

 Least monthly quantity in May . . . . 1*125 

 Total amount for the year near the ground 34*665 

 Total amount for the year 23 feet high . 31*165 

 N. B. The barometer is hung up in the observatory 50 feet 

 above low-water mark ; and the self-registering horizontal day 

 and night thermometer, and De Luc's whalebone hygrometer, 

 are placed in open-worked cases, in a northern aspect, out of 

 the rays of the sun, ■ ten feet above the garden ground. The 

 pluviameter and evaporator have respectively the same square 

 area : the former is emptied every morning at 8 o'clock after 

 rain, into a cylindrical glass gauge accurately graduated to 

 _£_th of an inch; and the quantity lost by evaporation from 

 the latter is ascertained at least every third day, and some- 

 times oftener, when great evaporations happen, by means of a 

 high temperature and dry northerly or easterly winds. 



Barometrical Pressure. — The maximum pressure was 

 not so high by y^th of an inch this year, as it was in the ge- 

 nial year 1822; the minimum was nearly T 5 n ths of an inch less, 

 and the mean 0*103 inch less. The mean pressure for the 

 present year corresponds very nearly with that for 1816. The 

 aggregate of the spaces the mercury has described in its al- 

 ternate rising and falling, is 10*58 inches greater; yet the 

 number of changes is 18 less than that of last year. For 181 

 days in which the moon ranged in North declination, the 

 mean pressure was y^^ths of an inch higher than that in the 

 204 days she ranged in South declination. 



Temperature. — The annual mean temperature of the ex- 

 ternal air a few feet from the ground, is nearly 2>\ degrees 

 less than that of the preceding year, and less than it has 

 been since the year 1820: but it corresponds exactly with the 

 annual mean temperature for the years 1817 and 1819. It is 

 a remarkable circumstance in the temperature of the air, when 

 the maximum height for the year does not exceed summer 

 heat, or 76 degrees, which was the case this year ; and, what 

 is equally as remarkable, it happened on thejirst day of June. 

 Even the cold and wet year 1816 produced a maximum tem- 

 perature of 78 degrees, which also happened in June. The 

 annual maximum temperature of the air has occurred in June 

 five years out of the last nine, viz. in 1816, 1817, 1820, 1822, 

 and 1823. 



The annual mean temperature, and the mean at half-past 

 8 o'clock A.M. this year, correspond within three quarters of 



a degree ; 



