102 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. Lxii. 



The fall of 1881 corresponds with a cold and relatively 

 dry summer. 



The gradual rise from 1881 to 1886 occurred during a 

 period of great summer rainfalls and low temperatures. 



The slight fall in 1887 and 1888 agreed with a period 

 of drought. 



The rise in 1889 and 1890 occurred during moister 

 seasons than the preceding two. 



The fall in 1891 and 1892 was probably due to the 

 greater cold of the summers, to a gradual decrease of 

 humidity, and partly to the low rainfall of 1892. 



The slight rise in 1893 was mostly due to the high 

 summer temperature, While sunshine, rainfall, and humidity 

 also increased from 1892. 



The curve of Scots pine, E, agrees with larch A, in 

 having maxima in 1859, '80, and '93, and minima in 

 1885 and 1892 ; and with spruce B, in having maxima 

 in 1857, '63, '73, '80 '90, and '93, and minima in 1858, 

 '60, '78, '85, and '92. 



This seems to show that Scots pine agrees more closely 

 in its requirements of meteorological conditions with spruce 

 than with larch'. 



The tree was 100 years old at the section, and at that 

 age the influence of the external conditions are not so 

 quickly perceptible in the annual rings as they are when 

 the tree is only 50 or 60 years old. 



As the curve has no striking rise or fall it will be 

 sufficient to mention only tlie chief periods of the tree's 

 growth. 



The warm dry years 1857 to 1859 account for the 

 maintenance of the increment, and the warm summer of 

 1857 corresponds with the maximum in the curve. The 

 cold, wet, and cloudy summer of 1860 caused a fall: 

 the warm summer of 1861, in spite of increased rainfall, 

 caused a rise, which was maintained through the dry period 

 until 1866; although the summers of 1862-63 were 

 cold, the sunshine was much above the mean. The cold, 

 wet, and cloudy year 1867 caused a very sudden fall — 

 the most rapid fall in the wliole curve. 



There was a slow but gradual rise until 1876 during 

 a period of warm, sunny summers. The heavy summer 



