8 The Bulletin. 



surprised to find that large trees uprooted by a storm have a much 

 shallower root system than one would have expected. On the other 

 hand, tree roots are sometimes found deep in wells, but on examina- 

 tion it will be found, too, that they adhere only to the air-exposed 

 surfaces. In cities, where filling-in is done to raise the grades of 

 streets, the deeper covering of the tree roots is almost always fatal 

 to shade trees. The same thing is often seen where lumber mills 

 blow out their piles of sawdust about the roots of growing trees. 

 It is not that the sawdust in itself is injurious, but that it suffo- 

 cates the tree roots by burying them beyond the reach of air. 



ATMOSPHERIC DRAINAGE AND FROST PROTECTION. 



In mountain regions, besides the draining of water from higher *to 

 lower levels, there is a similar drainage of air. This latter might 

 seem to be of trilling importance in fruit growing, but it is in fact one 

 of the most important considerations, for it tends greatly to avert 

 frost. Freezes and frosts are undoubtedly the greatest hazard of the 

 business of fruit growing. ~No disease or depredator destroys half so 

 many hopes and dollars for the fruit grower as a few hours of frost. 

 We are told that "the frost falleth alike on the just and on the un- 

 just," but in seasons when the daily papers are heralding reports that 

 an untimely frost has taken the entire fruit crop of the State some 

 lucky fellow high up in his mountain coves, with not too many good 

 works to his credit, has his entire crop saved as if by miracle. Frosts 

 appear to strike in a very erratic manner ; they are, however, like 

 other phenomena of nature, subject to very definite laws. It is well 

 known that as air becomes heated it ascends, and as it cools it becomes 

 heavier and falls. On sloping ground air as it cools passes down 

 from higher to lower levels. Other things being equal, low lands are 

 more frosty than higher lands, because the cold and frosty air drains 

 from the higher and settles into the lower levels. A corn field in the 

 fall gives one of the best illustrations of the places most subject to 

 frost and those also which are exempt. On the bottom lands the 

 blades and stalks will almost invariably show where frost has bitten 

 first. Up on the hillsides and higher elevations the corn will often 

 be found growing fresh and green, while in the bottoms below not a 

 green stalk can be seen. Where knolls occur in bottoms they will 

 often be seen to lift their green-clad sides out of the blighting frost- 

 laden atmosphere of the surrounding valley. Air drainage is just as 

 natural as water drainage, and for orchard locations is just as impor- 

 tant a consideration. 



The frostiest locations, and those therefore to be most avoided, are 

 valleys shut in on all sides. To the uninitiated these places would 

 appear to be most admirably protected, but they are veritable frost 

 pockets. On cold nights they receive the cold air from higher regions, 

 and frosts and freezes in them are inevitable. Once while traveling 



