Book III. 



SHELTERING FARM LANDS. 



685 



they do in an open exposed country. In the breeding of cattle, a sheltered farnij or a 

 sheltered corner in a farm, is a thing much prized ; and, in instances where fields are 

 taken by the season for the purpose of fattening them, those most sheltered never fail to 

 bring the highest rents, provided the soil be equal with that of the neighboring fields 

 which are not sheltered by trees. If we inquire into the cause, we shall find, that it 

 does not altogether depend on an early rise of grass, on account of the shelter afforded 

 to the lands by the plantations ; but, likewise, that cattle which have it in their power, in 

 cold seasons, to indulge in the kindly shelter afforded them by the trees, feed better ; 

 because their bodies are not pierced by the keen winds of spring and autumn ; neitiief 

 is the tender grass destroyed by the frosty blasts of March and April. [Plant. Kal* 

 p. 121.) 



4224. The operation of skreen plantations, in exposed situations, Marshal observes, is 

 not merely that of giving shelter to the animals lodging immediately beneath them ; but 

 likewise in breaking the uniform current of the wind, shattering the cutting blasts, 

 and throwing them into eddies : thus meliorating the air to some distance from them* 

 Living trees communicate a degree of actual warmth to the air which envelopes them* 

 Where there is life there is warmth ; not only in animal, but vegetable nature. The 

 severest frost rarely affects the sap of trees. Hence it appears, that trees and shrubs 

 properly disposed, in a bleak situation, tend to improve the lands so situated, in a 

 threefold way, for the purposes of agriculture : namely, by giving shelter to stock ; by 

 breaking the currents of winds ; and by communicating a degree of warmth or softness 

 to the air, in calmer weather. 



4225. The proper disposal of skreen plantations for this purpose is in lines across the 

 most offensive winds, and in situations best calculated to break their force. Placed 

 across valleys, dips, or more open plains, in bleak exposures, they may be of singular 

 use. Also on the ridges, as well as on the points, and hangs, of hills. 



4226. The width of skreen plantations ought generally to be regulated by the value of 

 the land for agricultural uses, and the advantages of the situation for the sale and deli- 

 Very of timber. In ordinary cases, from two to four statute poles may be considered as 

 an eligible width. 



4227. The form of plantations for shelter, however, will not in every case be that of 

 a stripe or belt of uniform width. In hilly, rocky, and other situations, different forms 

 vvill suggest themselves according to the situation and the objects in view. In rocky 

 abrupt sites (^^. 549. ;, the plantation will consist of a number of masses (, 6,c)j 

 of forms determined by the rocks and precipices, among which some of the most 

 valuable pasture may be left as glades (f/, e), for use, effect, and for the sake of game. 

 Strips and hedges for sheltering, or separating arable lands, should be formed as much 

 as possible in straight and parallel lines, in order not to increase the expense of tillage. 



