Calendar of Nature, 5QT 



The double lines, marked b, show the motion of the mercury in the ba- 

 rometer ; tswy the mean temperature of the air near a south garden-wall ; 

 t, the mean temperature in the open air and in the shade ; d, the dew-point ; 

 and min. ty the minimum temperature in the open air at night. 



The coldest day in August was on the 26th : mean temperature of that 

 day 48-5°; extreme cold 39" three feet above the surface, and 31° on the 

 grass ; wind westerly. The warmest day in August was on the 4th : mean 

 temperature of that day 60*5° ; extreme heat 69° ; wind westerly. The mean 

 temperature for the month was 54*4°, nearly 4° below the average tempera- 

 ture for that month for the seven preceding years. There were 6 days of 

 brilliant, and 12 of partial, sunshine; 13 days were cloudy. The wind blew 

 from easterly points on 9 days, and from westerly points on 22 days. There 

 were no remarkably loud winds during the month ; but on the 8th, about 

 5 o'clock in the afternoon, there was a loud and violent thunder-storm, ac- 

 companied with hail ; and at Errol, in the centre of the Carse of Gowrie, ice 

 fell in large pieces of the size of a cubic inch and upwards, covering an area 

 of about 500 acres, on which the corn crops were completely denuded of 

 the partially filled grain, and the green crops of their foliage. The minimum 

 temperature during the night was 46°, and yet much of the ice lay undis- 

 solved in ditches and shady places till near noon the following day : a 

 phenomenon of this nature is seldom observed in Scotland. The coldest 

 day in September was on the 23d : mean temperature of that day 49° ; 

 extreme cold 41° ; wind variable. The warmest day was on the 27th j mean 

 temperature of that day 58° ; extreme heat 60° ; wind S.W. There were 

 8 days of brilliant, and 8 days of partial, sunshine ; 14 days were cloudy : 

 the wind blew from easterly points on 5 days, and from westerly points on 

 25 days. There were loud gales on the 11th, 19th, 20th, 24th, and 25th. 

 The mean temperature for September was 52*9° ; the ordinary temperature 

 for that month is 54*7°. The fall of rain during the two past months has 

 been excessive, amounting to 10'39 in. ; and from the moist state of the atmo- 

 sphere, which will be observed by the line repi esenting the dew point being 

 so near the mean temperature, little evaporation could take place : conse- 

 quently the soil has been all along exceedingly moist. This, accompanied with 

 a temperature under the ordinary mean, has protracted the ripening process 

 to a later period in the season than usual. The general clouded state of 

 the atmosphere, too, has retarded the ripening of wall-fruits ; for it is sun- 

 shine that communicates that heat to walls by which fruit is ripened in the 

 same space of time with those of the same kind some 6° or 7° farther south 

 in the open air. Too much stress is sometimes laid on walls giving out 

 much caloric throughout the night, by writers on gardening. On a cloudy, 

 day, or at midnight, a thermometer, within 6 in. of a south brick wall, will 

 not indicate above a half degree higher than one on a north aspect. During 

 clear sunshine, the difference in favour of the south wall is from 10° to 12°; 

 but they uniformly approximate a short time after sunset : taking, there- 

 fore, the mean of the daily extremes of the temperature of a south wall in 

 September, when the atmosphere was for the most part cloudy, it did not 

 exceed the common mean much above 2°. In August, the difference in 

 favour of a south wall is as 4*2°. 



In the flower-border, the LiXmm candidum opened its elegant flowers on 

 the 1st of August ; Timothy grass in fields came in flower on the 2d;^ the 

 Digitalis ferruginea on the 5th, four days later than last year ; Coreopsis 

 verticillata on the 15th, five days later than last season. Peas that came 

 in flower in the field by the 12th of July, were ripe by the 8th of Septem- 

 ber, a period of 58 days : mean temperature of that period 56*6° ; depth of 

 rain 7| in. The excess of moisture in the air and in the soil prevented the 

 pods from filling, and also retarded the ripening process. Barley that came 

 in the ear on the 16th of July was ripe on the 10th of September, a period 

 of 56 days ; mean temperature of that period 56-6" : a curious coincidence 



