THE ELM. 



433 



avenue, Called " The Long Walk," at Windsor, 

 was planted at the beginning of the last century. 

 Most of the trees have evidently passed their 

 prime. The most profitable age of elms, both 

 for quantity and quality of timber, is, probably, 

 about fifty or sixty years. The central parts of 

 a tree get indurated, lose their natural sap, and 

 are apt to absorb moisture, by which they soon 

 rot on exposure to the air, long before the dry 

 rot consumes them, shielded as they are by the 

 external parts. The predominance of resin in- 

 soluble in watei-, and not liable to be acted on 

 by the acids of the atmosphere, is the cause why 

 the pine and the larch are more durable than the 

 silver fir and the spruce. It is possible that the 

 elm is injured by too much humidity in the soil 

 upon which it grows ; and that the Dutch elm, 

 which is usually classed as a different species 

 from the common elm, and of which the timber 

 is inferior, may be merely the common one de- 

 based in the humid soil of Holland. 



The elm rises to a greater height than the 

 generality of English forest trees, with a foliage 

 at once full and hanging loosely, and thus ca- 

 pable of receiving great masses of light, and of 

 producing "the chequered shade," which im- 

 parts such a sparkling beauty to woodland 

 scenes. 



The elm has been always considered as one of 

 the trees which can be most safely transplanted 

 after attaining considerable size. Evelyn gives 

 several accounts of trees of this species being thus 

 removed into other soils. 



The shelter which trees afford to the soil is 

 one of the surest means of increasing the warmth 

 and fertility of a country ; and many districts 

 have been converted from bleakness and sterility, 

 to productiveness and value, by plantations of 

 timber. This is particularly the case where the 

 wind blows over those cold surfaces of heath and 

 morass, which occur in the northern parts of the 

 island of Great Britain. The subject has not 

 been investigated with that attention which its 

 importance merits; but appearances render it 

 highly probable that the spawn of mosses and 

 lichens are wafted by the winds; and that if 

 these winds are not purified from the pestilent 

 spawn, they spread a noxious vegetable growth 

 over what would otherwise be fertile land. In 

 this way belts of plantations act as a sort of fil- 

 ter for the winds. The trees next to a marshy 

 heath have been covered with lichens, so that 

 no part of the bark was visible; while in the in- 

 terior of the belt, and on the side most distant 

 from the barren track, the bark has been free 

 from these parasites. Further, after the trees 

 have attained sufficient size to shelter the land, 

 the moss has disappeared from it, and the soil 

 has become fit for the production of valuable 

 crops. Nor is it on trees alone that this effect 

 of winds, from cold and watery tracks, may be 



perceived; for those sides of ancient and elevated 

 buildings which are opposed to them are in- 

 crusted with moss and lichen, while the other 

 sides are comparatively clean. To any one who 

 has paid much attention to the more sterile dis- 

 tricts of the country, it is matter of every- day 

 notice, that nothing tends so much to confine 

 within bounds the plants which are hostile to 

 the grasses and cultivated crops as timber ; and 

 this being the case, it follows that the means of 

 procuring an instantaneous shelter of grown tim- 

 ber are, at the same time, the surest means of 

 procuring, comparatively, instantaneous fertility. 

 In many instances the land, when not sheltered 

 by timber, has returned to its original sterility, 

 whenever it has been allowed to lie in grass; but 

 when so sheltered, the pastures have retained 

 their greenness for years, and, instead of being 

 deteriorated, have been improved by remaining 

 for a few years out of tillage. 



The transplantation of grown timber trees ap- 

 pears, indeed, to be the only way by which shel- 

 ter can be restored to cold, bleak, and exposed 

 districts. The remains of large trees, which are 

 found in the mosses and bogs of such districts, 

 prove that once both the soil and climate have 

 been adapted to the production of wood. This 

 is true not only of those countries where timber 

 is still to be found in warm and sheltered places, 

 but in those dreary climes where now hardly a 

 shrub is to be found, and where, although young 

 timber be planted, it will not grow — as in the 

 counties of Sutherland and Caithness, the Ork- 

 ney and Shetland isles, and even in Iceland it- 

 self. The latitude has not altered since the trees 

 which are found in the peats-bogs of those re- 

 gions were green and flourishing upon the sur- 

 face; and if the soil and the climate have been 

 deteriorated, it must have been by exposure to 

 the damp and bleaching winds. Those winds, 

 as has been said, prove fatal to young trees; but 

 it is probable that, if grown timber, of the more 

 hardy sorts, could be introduced as a shelter, the 

 land would recover its former fertility, and the 

 landscape its ancient beauty. 



The observations of philosophical travellers 

 and inquirers, with regard to the whole of the 

 northern countries of the world, whether in the 

 eastern continent or the western, confirm these 

 remarks. Sir Hans Sloane, in his account of the 

 bogs of Ireland, mentions that a great part of 

 those districts which are now covered by that un- 

 profitable substance, must have been once clothed 

 with forests of trees. Broke, in his Winter in 

 Lapland and Sweden, notices the same change as 

 having taken place in the north of Lapland and 

 the islands. Sir George Mackenzie and others 

 observe the same as being the case in Iceland; 

 and Heame mentions that large tracts of the 

 northern parts of America, which at his visit 

 were covered with moss and swamp were forests 

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