nno STATE POMOLOGICAL SOCIETY. 



certain priiporlicii oftlu'ir laiiil in (iinlxr. If, now, (hut amount on facli I'aiui, 

 bo it a. third, a fourth, or even aa eighth or tenth of tlie wliolo, be located, not 

 in a compact body in the rear, bnt rather in an extended l)elt ab)np tlie exposed 

 Rides, nay th(^ west and nortli, tlu- result will be ihat the whole eonntry will 

 become checkered over with windltreaks, and the general elleet will be nenrly 

 equivalent to that of a continuous forest, so far as protection Irnm wind and 

 probable effect upon rainfall arc concerned. 



THE QUESTION OF RAINFALL 



\h not, however, by any means Ihe only one that arises in connection with 

 that, of forest and litulxM" protection. The ability to retain and utilize mois- 

 ture must he considered as only second to the ability to secure its precipita- 

 tion. It is a well known fact that the moisture of the soil often disappears 

 with wonderful ra|)idity under the inlluenee of high winds, when, as in the 

 absence of limber growths or other protection, they cotne to sweep directly 

 over the surface, wlnh^ lew can have failed t,o observe that a covering of timber 

 serves to restrain the motion of the wind, or in other words, to more or less 

 perfectly imi)riso!i a stratum of the atmosphere ne.Kt the surface, and of the 

 height of the liml)er growth, and thus to arrest in an impoi'taiit degree the 

 dissipation of the surface moisture, — a result, to say the least, fully as advan- 

 tageous as an equivalent increase of the rainfall. 



It is doubtless true that., aside from the abstraction of moisture from the soil 

 by |)lanls during the process of growth, a mere covering of growing herbage 

 must, in a slight degree atul in the same nnmner, restrain such evafxtration 

 from the surface; while t.ho fruit-grower may congratulate himself with the 

 consideration that a ))lantation of fruit trees or vines must, when well grown, 

 Ix'come still uu)re edective. Still it should not be forgotten that su(di shelter 

 will ])rove ell'ective al)out. in ])rop(n-tion to the height of the growth, and the 

 perfectiH'ss with which it shall act, as a barrier to the motion of such surface 

 stratum of air. A regular open plantation, such as our orchards generally are, 

 will, in this respect, be usually less effective than (x^casional dense windl)reaks 

 consisting of fully-grown forest, trees, when extending in a direction transverse 

 to the motion of the wind, whili; the elfect of such an aggregation or system of 

 timber belts as has been heretofore proposed, would be to largely restrain the 

 onward movement of the altnosphere, with the accompanying dissipation of 

 the surface nmisture, even in the intervening spacH'S, 



W«! have assumed, as we doulH not we are warrauteil in doing, that 



SirUFAOlC KV.\ I'OHATION 



proceeds nearly in (lu- ratio of the velocity of the winds at the surface, and wo 

 (iaunot better illustrate the increased result from free exposure than by refer- 

 ence to a ca.se in which the agijregau'd effects are made nuinifest to the eye of 

 the ob.server, that of the drifting of winter snows. No <loul>t we all have had 

 occ^asion to ub.serve that in cases in which froui the joining of clearings along 

 a highway, or from other causes, a range, sometimes of several miles, is left 

 open to the westerly storm, the north and south fences soon beconje lined with 

 the accumulated drifis, while tlu* north and south streets are pretty sure, if 

 fenced, to become buried, often across their entire width and from top to top of 

 the fences, while perhaps only a few rods distant, but under the lee of a forest, 

 even though from forty to eighty rods away, very little drifting will be found 

 to have occurred. 



