ARBORICULTURE. 27 \ 



supplying the secondary springs and outlets in the lower levels. 

 When the source is ascertained, a drain should be cut to the depth 

 of the strata through which it passes, so as to obstruct its progress. 

 It should be made sufficiently deep, or the water will continue to 

 pass under it, and the work will be useless. From this main 

 drain formed across the declivity, other secondary drains should 

 be made to conduct the water thus collected, from the source to 

 the most convenient outlet. It would be incompatible with the 

 space of these pages to enter into details of this subject. Elkin- 

 ton's mode of draining, as given in Johnstone's Treatise on the 

 subject, is on the above principle, and shows with precision the 

 advantages of it, and with how much facility lands, which by the 

 old method of draining were considered incapable of being pro- 

 fitably improved, may be made fit for planting and returning a 

 valuable produce of timber. 



Clayey soils which are rendered barren by surface w T ater stag- 

 nating upon them, may be made to produce valuable timber by 

 the simple process of constructing open drains, and forming the 

 surface between these into ridges. 



On steep acclivities, rocky soils, and thin heath, or moor 

 lands, incumbent on rock or shale, where ploughing or trenching 

 is impracticable, a depth of pulverized soil cannot be obtained 

 for the reception of the roots of trees of more than two, or at 

 most three years' growth ; the mattock planter, diamond dibble, 

 and spade, can be used with the best effect, To attempt any 

 more expensive preparation on such lands, than may be made by 

 these implements for the reception of the individual plants, would 

 be injudicious. For the preparation of heath soils, incumbent on 

 sand or loose gravel, an improved paring plough (Plate 110 ? 

 Fig. 9 and 10), which we call Fyshe Palmer's planting plough, 

 is a valuable implement. 



The plough consists of two mold boards as in common use, but 

 resting on a triangular and somewhat convex plate of iron 

 (Fig. 9). This iron plate is furnished with sharp steel edges 

 rivetted to it (Fig. 10, c). The fixed share (a, Fig. 10), 



