2392

ARBORETUM AND FRUTICETUM.

PART III.

pine, as nurses to the larch, some part of the plantations which had been madeabout the year 1800, before the period of seedling plants being used. This, astbe duke observes, was ‘the dwarf nursing the giant.’ In 1817, most ofthese Scotch pines had not attained a height exceeding 3 ft., while the larches,which they were intended to nurse, were from 15 ft. to 20 ft. high. In thelower part of the same plantation, where the Scotch pine had grown to 20 ft.in height, the larch exhibited a stature of from 30 ft. to 40 ft.; and, in theinstance before referred to, in an elevated situation, at 900 ft. above the sea,where the Scotch pines were more than 42years old, they were only 5 ft. and Oft.high ; whilst the larch, in the same situation, and planted 10 years after them,had reached up from 40 ft. to 50 ft. in height. In 1816, the duke measured alarch, on a pinnacle of the highest ridge of the ground alluded to above, atonly 9 years after planting, which was quite straight and vigorous, and stood16 ft. high, and the nearest Scotch pine to it was only 2 ft. 6 in.” On thispassage, Mr. Gorrie remarks, that the Scotch pine should never be mixed withthe larch in plantations, as it will produce rot.

Rate of Growth of the Larch . “ Taking the average height, then, of an averagelarch of 8 years from the seed at 11 ft., it will be ftearly accurate to allow16 in. as the annual growth, till the tree is 50 years old ; and after that, only10 in. per annum, for 22 years longer, as the length of the tree lessens ingrowth as the bulk of the wood increases. These data give a larch tree of 72years of age a height of 93 ft. 4 in.; a fair average, agreeing with actual expe-riment. The shoots of larches beyond 35 years of age are heavier, though theyare not so long as those of younger trees. The larch, like the oak, puts forthtwo shoots every year, the one in spring, the other in autumn. The springshoot has no lateral branches : the autumnal shoot pushes out like the springone ; but, at the time this process is going on, the spring one is throwing outlateral branches. These lateral branches are firm and woody. In regard tothe growth of the girt, a larch tree, on an average, will acquire 1 in. in girtper annum, till it be 24 years old; and from that time, till it has acquired theage of 72 years, it will grow 1A in. in girt every year; thus,

In 24 years, it will be 2 ft. in girt, at 1 in. per annum.

48 — more 5 — 1£ -

In 72 — it will be 7 ft. _

The larch begins to make wood at 24 years of age.

At 50 years old, it will contain 26 cubic feet of wood.

60 — — 14 — more.

72 — — 20 — _

In all, 60 cubic feet of wood; or one load of 50 cubic— feet, and 10 ft. more.

“ These results correspond exactly with the quantities which the duke ob-tained at these respective ages. Larch appears to be on its greatest increasefor timber from 57 to 72 years old. A larch containing 50 cubic ft., or oneload of timber, is quite fit for naval purposes. At half that size it is suitablefor every country purpose.

“ A few Examples of the sizes of the timber which the duke felled may notprove uninteresting. In 1806, twenty larches, at tbe age of 64 years, were cutfor centres to the bridge building at Dunkeld . These trees having been drawnup by close planting, they were from 105 ft. to 109 ft. in length ; their girtswere from 5 ft. to 5 ft. 4 in.; and they averaged from 80 to 90 cubic feet of tim-ber. In 1810 and 1811, 600 trees were felled at Dunkeld and Blair, to sendto Woolwich dockyard, the aggregate amount of which was 606 loads. Thetimber was much admired by the best judges. One of the logs contained 83 ft.of wood.

“ The Larch will thrive better in a northern than in a southern Exposure, till it isabout 30 years of age; but, after that period, there is no perceptible difference.This circumstance may be explained by the favourable effect of an equabletemperature on the health of trees. The vicissitudes of frost and thaws must