86 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



In the year 1901 it was underplanted with spruce, and has since 

 been thinned to prevent excessive shading. 



10. A spruce wood mixed with pine and birch and which has 

 also developed from a forest field, the south part is twenty- 

 two and the north part thirty years old. The continued utilisation 

 of the field for agriculture was prevented by the nun- moth 

 calamity. A severe cutting out of the suppressed spruce and 

 pine trees, also the cutting out of birch to prevent whipping is 

 contemplated this year. 



11. A thin 75-year-old pine wood with 3525 cubic feet per 

 acre. This pine wood was formed seventy-five to eighty years 

 ago after a hailstorm had completely destroyed a young spruce 

 wood on the same area. Formerly it contained a good many 

 spruce, but these were defoliated in the year 1890 and had to 

 be cut out ; since then the pines heve shown a strong light- 

 increment. Cutting out of the less vigorous material yields 423 

 to 564 cubic feet per acre. 



Thursday, ^th August 1909. 



GRAFRATH. 



The Royal Experimental Forest-Garden of Grafrath Hes about 

 20 miles to the west of Munich, 1870 to 1968 feet above sea-level. 

 It is situated on a terminal moraine. There is considerable 

 diversity in soil and aspect. 



The climate may be described as that of the cooler Fagetum, 

 with an average annual temperature of from 44'6 to 59° F. during 

 the four principal vegetation months (May to August inclusive). 

 The average humidity of the air during that period is 75 per 

 cent. The annual rainfall is about 27 "5 inches. 



First frost in October (seldom in September). October 1908, 

 14° F. Last frost in May, though sometimes in June. On 6th 

 June 1868, 21-2° F. Lowest temperature in winter, -13"' F. 

 In the lowest lying part of the garden, - 36'4° F. 



The Soil. — This varies within short distances from heavy clay 

 to inferior sandy, and gravelly soil. On the higher ground both 

 good and bad soils occur ; this is very well shown in the growth of 

 the larch. On the whole the soil is neither very good nor very bad. 

 The southern slopes after clear felling tend to become heathy. 



Size of the Garden. — The experimental plots situated to the 

 south of the railway, from Munich to Lindau, cover 98 acres. The 



