274 



Coombe Plantation, Keswick. [July, 



sequently often very knotty and coarse, and has little or no 

 heartwood. 



Scotch pine might, with advantage, have been grown on 

 some of the low ridges at present occupied by larch. As 

 shown by the rounding off of its crown, Scotch pine has at 

 its present age (62 years) completed its principal height- 

 growth under these conditions. 



Silver fir is much less abundant than either spruce or 

 Scotch pine, and is growing only in a sheltered locality at 

 1,250 ft. elevation. The growth there has been remarkably 

 good, and 21 trees felled in 1907 had an average volume of 27 

 cubic ft. quarter-girth. It seems probable that this species, with 

 its shade-bearing properties, would be extremely useful for 

 planting in mixture with the light-demanding larch. Its slow 

 growth in early youth should give the larch a good start, and 

 at the same time it should survive the shade of the latter until 

 such time as heavier thinnings were made, when it should 

 begin to forge ahead. 



With regard to the relative rates of growth of larch, spruce, 

 and Scotch pine, it may be said that spruce is now for the 

 "first time taking the lead, and overtops the larch by a foot or 

 so, while the Scotch pine is overtopped by the larch by a 

 similar amount. Under such conditions of growth, a mix- 

 ture of spruce and larch should thrive well, as far as the 

 larch is concerned, although in such a mixture the timber 

 of the former is hardly likely to be of the best quality. 



The Experimental Groups. 



Experimental groups of trees, for the most part larch, 

 were picked out in the year 1873, and the girths of the indi- 

 vidual trees recorded from year to year. 



Unfortunately, no records of the height-growth from period 

 to period have been kept, and to fill this deficiency a sample 

 ; tree, equalling as nearly as convenient the average height of 

 the group, was felled in the vicinity of each group. Each 

 tree was then cut up into sections varying in length from 

 4 to 6 ft., the rings at each section carefully counted, and 

 the diameters measured. In this way it was possible to re- 1 

 construct the height-growth, and to arrive at approximate 

 form factors for the volume of larch. The form factors so 



