270 EXACT PROGRESSIVE- MEASUREMENT OF TREES. 



wood ; 1879 was much the reverse. Spring was backward, 

 though not otherwise unpropitious ; summer and autumn were 

 unprecedentedly cold and sunless, and September was especially 

 so, hindering thereby the ripening of young wood and buds for 

 the following year. The early winter of 1879-80 was distin- 

 guished by a severity of frost of which there had been no record 

 in this country. The spring of 1880 was again backward, and 

 the summer under average for sun and heat, but superior in these 

 respects to 1879. August was a fine month, and September, 

 equally fine in all respects, was highly favourable to budding, 

 and to the ripening of J'oung wood. But the winter of 1880-81 

 set in with a severity surpassing that even of the previous year. 

 The spring of 1881 was for a third time backward: the summer 

 and autumn were cold and sunless, except the month of Sep- 

 tember, which, in the west country at least, was favourable. In 

 one or more of these four conditions for vio^orous growth — a 

 fine September, a winter of no great severity, a forward spring, 

 and a genial summer and month of August — the last three years 

 have been more or less seriously faulty. The following conse- 

 quences have been indicated by the test of exact measurement : — 

 Of seventeen leaf-shedding trees in the Botanic Garden and 

 Arboretum, comprising four of beech, two of lime, two of syca- 

 more, a sweet chestnut, a horse chestnut, a flowering ash, a tulip 

 tree, a hawthorn, a birch, a Turkey oak, an American red oak, 

 and a hornbeam — all of them in 1878 healthy vigorous trees, from 

 about 40 to 130 years of age — the aggregate trunk-growth in that 

 favourable year was 12 8 inches, and in 1879, 1880, and 1881, 

 6*9, 5'6, and 94 inches. I do not know how to explain their 

 partial and considerable recovery during our late cold summer 

 and August except by reference to the fine budding season in 

 the preceding September and the absence of any severe frosts 

 during last spring ; in consequence of which, I presume, it was 

 that forest trees generally were well clothed with fine foliage. 

 It is not, of course, to be understood that each species followed 

 in its growths each year the ratio of these aggregates ; far from 

 it. But the number of observations on the several species has 

 been too limited to justify the separation of any of them. One 

 species, however, I have detached on account of its anomalous 

 growth and resistance to severity of climate. This is the Hun- 

 gary oak {Qiicrcus pxnnonica, var. conferta). In the spring of 

 1878, a tree of this species, planted out ia 1865 on a northern 

 slope, exposed to direct north and north-west winds, but not to 

 the north-east and east, was 23*6 inches in girth at the nar- 

 rowest part of its trunk, 3 feet 4 inches from the roots. In 

 October 1881 it was 30'3 inches. Its increments in the last 

 four succ33sive years have been 1*8, 1*7, 1"4, and 1*8 inches. 

 As two other youngar trees not measured till the spring of 1880 



