284 



Calendar of Nature, 



Register kept at Annat Gardens, Perthshire, N. lat. 56° 23^', above th« 

 level of the sea 172 ft., and 15 miles distant from the coast, by the mean 

 of daily observations, at 10 o*clock morning and 10 o'clock evening. 

 The shaded part of the columns, representing the evaporating gauge, 

 sliows the water remaining unevaporated at the end of every ten days, when 

 the gauge was again filled to the brim ; the open space from the top con-* 

 sequently shows the depth evaporated each period. The rain-gauge was 

 emptied at the end of every ten days, and the shaded part of the column 

 shows the depth of the fall of rain. The dotted line t shows the mean 

 temperature ; the line marked d shows the mean point of deposition, or the 

 temperature at which part of the moisture held in solution in the atmo- 

 sphere throughout the day began to fall in the shape of rain or dew ; the 

 double line b shows the mean height of the mercurial column in the baro- 

 meter in inches and tenths. As lines representing the monthly meanj 

 produce confusion, they are not inserted, and will appear in figures in the 

 Calendar of Nature. 



Diagram, showing at one view the Mean Temperature for April and May, 

 from A.D. 1822. 



76 



By this it will be seen that the mean temperature in April of the present 

 year is lower than in any of the seven years immediately preceding. The 

 dotted lines show the mean temperature for April and May in each year ; 

 a shows the mean for April ; and we the mean for May for the eight years 

 succeeding 1822 inclusive. The temperature for April this year is some- 

 thing more than 3°, while that for May is rather more than a° above the 

 ordinary average. The fall of rain for the two months is only 3 in. 45 

 decimal parts, or about l|in. less than on any of the two former seasons 

 during the same period. The coldest day was on the 2d of April ; mean 

 temperature of that day, 36-5°,* extreme cold, 31*5°; wind,N. The warm- 

 est day for the two months was the 23d of May : mean temperature of 

 that day, 56°; extreme heat, 62°; wind, W. The mercury in the baro- 

 meter was highest on the 26th of May; height, 30 in.; wind, E. : and 

 lowest on the 15th of April; height, 2825 in.; wind, W. There were 

 loud gales of north-easterly winds on the 2d and 29th of April, and north- 

 westerly winds on the 4th of May, 



