78 Meteorological Observations for May 1827- 



Therm. Max. 72° May 21. Wind W.— Min. 40° May 7 & 12. Wind NE. 

 Range 32°.— Mean tenip.of exter. air 56°-31. For 31 days with in CS 53-19 

 Max. var. in 24 hours 21°-00-Mean temp, of spring water at 8 A.M. 50°-22 



De Luc's Whalebone Hygrometer. 



Greatest humidity of the air in the evening of the 5th .... 95° 

 Greatest dryness of the air in the afternoon of the 13th .... . 33 



Range of the index 62 



Mean at 2 P.M. 54°-l— Mean at 8 A.M. 60°-l— Mean at 8 P.M. 70-9 



of three observations each day at 8, 2, and 8 o'clock . . 61-7 



Evaporation for the month 3-05 inch. 



Rain near ground 2-125 inch.— Rain 23 feet high 1-965 inch. 



Prevailing Wind S.W. 



Summarij of the Weather. 

 A clear sky, 3; fine, with various modifications of clouds, 14^ ; an over- 

 cast sky without rain, 7 ; foggy ^ ; rain, (i. — Total 31 days. 



Clouds. 



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



20 9 28 22 21 18 



Scale of the prevailing Winds. 



N.W. Days. 

 31 31 



General Observations.— This month has been alternately dry and wet, 

 with frequent gales of wind; and although it has rained more or less on 

 eighteen different days, yet the aggregate quantity has only been sufficient 

 to keep the herbage and vegetation in a good growing state, the light 

 showers having been quickly dried up by the sunshine and winds. As April 

 was rather dry, the showers in the first part of the period were very bene- 

 ficial ; for they in some measure counteracted the blighting effects of the 

 easterly winds, and hoar-frosts on several mornings. From the 21st to the 

 end of the month the atmosphere was generally loaded with moist clouds, 

 which for several days were in contact with the earth's surface, and in their 

 passage afforded frequent irrigations, insomuch that the roots of the grass 

 have been much thickened, and bear a striking contrast to the appearance 

 last year ; the wheat plants changed to a fine verdant colour, and vegeta- 

 tion brought forward surprisingly. The bloom of the trees, in general, was 

 fine and luxuriant, and the state of the period, excepting two or three 

 cold days, fair growing weather: the temperature of the air, however, has 

 often been variable, and trying to delicate constitutions, and caused agues, 

 colds, rheumatism, &c. 



From six till after seven o'clock in the evening of the 25th, unusual at- 

 mospheric ^j/<<Ewo?HCTia presented themselves here, as exhibited in the an- 

 nexed figure, where the line HO represents the western horizon, S the 

 sun, abc three parhelia, each 22 J degrees distant from the sun's centre ; 

 they were nearly the apparent size of the sun, and composed of intermixed 

 prismatic colours, r/e, abroad whitish column of light reflected upwards 

 and terminated in a point ; g h part of an inverted arc of coloured vapour ; 

 ikl a solar halo 90 degrees in diameter, bounded by red, the interior pris- 

 matic colours being faint; and W k the prime vertical. When it is stated 

 that the solar halo is generally 45 degrees in diameter, the present one 

 being 90 degrees made the phacnomenon the more singular, especially as 

 no halo of the common extent could be traced within the parhelia; only 



two 



