SHELTER TO WINDWARD. 



17 



given period, at different temperatures, and with different velocities 

 of wind. Tlie following extracts are made from this table : — 



The shelter from drying winds, and the consequent protection 

 against rapid desiccation of ground, afforded by a wood, extends far 

 beyond the shade of the trees ; and thus the prevention of evapora- 

 tion by the wind becomes, in most cases, of more importance than 

 the prevention of evaporation by sunshine. 



Of the extent of such protection there are illustrations given by 

 Mr Marsh, in his treatise on the " Earth as Modified by Human 

 Action" (pp. 162-166). They are adduced by him in illustration of 

 the effects of forests on climatal temperature ; but tlje subjects are 

 correlated, and the statement by Mr Marsh will be afterwards given. 



It is not only to leeward that the beneficial action of a forest 

 in giving direction to the wind is felt ; in some respects the calm it 

 secures to windward may be equal in importance to that which it 

 ensures beyond. Some years since a stage coach from the head of 

 Loch Long to Oban was usually driven by a coachman whose jests, 

 and jibes, and pleasantries, and humours, often kept the occupant of 

 the seat beside him, and the occupants of the seat immediately behind 

 in roars of laughter foi miles. It is said that on one cold windy day 

 he had as occupant of the box-seat a Scottish Judge, one of the 

 Lords of Session, who remarked in many places sheep crouchino- on 

 the windward side of whin bushes, and after a time, calling the atten- 

 tion of the coachman to the circumstance, he asked him why they did 

 so, " To keep them from the wind, my lord," was the respectful 

 reply. This oallei forth the unhappy remark. " If I were a sheep 

 I would lie down on the other side of the bush." When forth came 

 without a moment's warning the rejoinder, " Ah ! but, my lord, if you 

 were a sheep ye wud hae mair sense !" The sheep and the coachman 

 were right. The beautiful curve of a snow-wreath shows what was 

 the course taken by the wind in its formation and indicates the course 

 usually taken by it in surmounting a barrier : a long sweep on the 



