supplement. AGRICULTURE AS PRACTISED IN BRITAIN. 



1339 



wheel (#) are in the proportion of one to five, so that, when the handle is turned with the ordinary velo 

 city of forty revolutions a minute, the saw will make '200 revolutions in the same time, in order to keep 



1176 



the edge of the saw in contact with the saw-draft, a vertical spindle (h), carrying the pulley (t), or one foot 

 in diameter, is placed at the outward extremity of the carriage ; the pulley (0 is put in motion by the 

 band (j) passing over a smaller pulley on the winch axle. On the spindle (A) there is also fitted a small 

 drum (A), capable of being disengaged at pleasure from the motion of the spindle by means of a clutch. 

 The cord (/), which passes round the pulley (m). in the ground frame, has one end attached to the carriage ; 

 while the other end, being attached to the drum, is coiled upon it when revolving along with the spindle, 

 thereby carrying forward the saw with a slow and uniform motion. When the operation is completed, 

 the small drum is disengaged, and the cord is allowed to uncoil, while the carriage is moved backward to 

 prepare for the next cut. For the support and guidance of the carriage, an iron segment (») is fixed upon 

 the lower part, which slides through eves in the ground frame ; and the machine is kept steady while at 

 work, by two iron dogs (grappling irons), the hooks of which are driven into the roots of the tree. The 

 certificates accompanying the model of this machine bear ample testimony to its successful application on 

 the large scale; and show that it can be worked, and carried from tree to tree, by two men. The ma- 

 •ihine here described is calculated lor felling trees from eight to twelve inches in diameter. (Highland 

 Sue. Trans., vol. ix. p. 276.) 



8273. Species and varieties of the larch. That extensively cultivated by the Duke of Athol is the 

 common white larch, Larix europa^a Dec. ; but the following other species or varieties were tried :_ 

 1. The Tyrol larch, with white flowers; those of the common variety being pink flowers. 2. The Tyrol 

 larch, with white flowers ; the cones also remarkable for their whiteness, and for being erect, not 

 cernuous. The shoots of the Tyrol larch are generally stronger than those of the common larch ; but 

 the foliage of both kinds is similar. 3. The weeping Tyrol larch, a variety of the common, with pen- 

 dulous branches ; but distinct in botanic characters from the iarix pendula, or black larch of North 

 America. 4. The red larch of North America, or 7,arix microcrarpa. This species is remarkable for the 

 great specific gravity of its w^ood, which is so ponderous that it will scarcely swim in water. Its cones 

 are shorter or smaller than those of the common larch, its branches weaker, and its leaves narrower. 

 5. The Russian larch, raised from seed procured by the Duke from Archangel, about the year 1806. 

 The bark is cinereous, not yellowish-brown ; the leaves come out so early that they are liable to be 

 injured by spring frosts. The Z.arix pendula, or black larch of North America, and iarix daurica of 

 Dr Fischer of Petersburgh, are distinct species, no examples of which exist at Duukeld or Blair. (Hurt. 

 Trans., vol. iv.p. 416.) " , 



>'J74. As an Appendix to the chapter on Planting, we shall here give some account ol the larch 

 plantation of Athol and Dunkeld, from the Transactions of the Highland Society, vol. xi. p. 165. to 

 p.219. It appears that the late Duke of Athol planted 15,573 acres, which contained 27,431,600 plants. 

 Of these 8 604.542 plants were larch. All these were planted in the slit manner, as by far the best. It 

 is stated in that paper that the larch will supply timber fit for ship-building, at a great height above the 

 region of the oak ; and that, while a seventy-four-gun ship would require the oak timber ol seventy-five 

 acres, it would not require more than the timber of ten acres of larch ; the trees in both cases being 

 sixty-eight years old. The larch in the neighbourhood of Dunkeld grows at the height of 1300 feet 

 above the level of the sea : the spruce at 1200 ; the Scotch pine at 700 : and deciduous trees not higher 

 than 500. The larch, in comparison with the Scotch pine, is found to produce three and three quarter 

 times more timber, and that timber of seven times more value. The larch, also, being a deciduous tree, 

 instead of injuring the pasture under it, improves it. It is remarkable that the woolly aphis, which 

 affected the larch plantations in most parts of Scotland for a number of years about the beginning of the 

 present century, never extended higher than about 600 feet above the level of the sea. 1 he late Duke 

 John the Second planted, in the last years of his life. 6500 Scotch acres of mountain ground solely with 

 the larch which, in the course of seventy-two years from the time of planting, will be a torcst ot timber 

 fit for the building of the largest class of ships in his Majesty's navy. It will have been thinned out 

 to about 400 trees per acre. Each tree will contain at the least fifty cubic feet, or one load ot timber, 

 which at the low price of Is. per cubic foot, only one half of its present value, will give lOOO/.per acre, 

 or in all, a sum of 6,500,000/. sterling. Besides this, there will have been a return of 71 per acre from 

 the thinnings, after deducting all expense of thinning, and the original outlay of planting, rurther 

 still, the land on which the larch is planted is not worth above 9rf. to 1*. per acre. After the winnings 

 of the first thirty years, the larch will make it worth at least 10s. an acre, by the improvement of the 

 pasturage, upon which cattle can be kept summer and winter. (High/and Soc. Trans., vol. in. P-"*-) 



8275. Soil for the larch. It is an error to suppose that the larch will thrive in all soils and m all situ- 

 ations. There are many kinds of soils in which it will not thrive, and ought not to be planted It has 

 been found that, in soils which have been turned up by the plough, and which have borne white crops. 

 the larch cankers. It cankers in wet situations also. In soils resting on a wet tally subsoil, it decaj a at 

 the heart, after arriving at forty years of age. In situations where water stands lor a length ol time 

 about the roots, it becomes fogged, or covered with lichens. Hot in all rocky situations, and particularly 

 those which are composed of mica slate, containing crystal ol garnets, among the fissures and fragments 



